diff --git a/DESCRIPTION b/DESCRIPTION
index 71237c5..c2c6054 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -22,7 +22,7 @@ Imports:
   rlang
 LazyData: true
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 6.0.1.9000
+RoxygenNote: 6.1.1
 Suggests: 
     testthat,
     knitr,
diff --git a/NEWS.md b/NEWS.md
index 427b6f2..06c9bfa 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,9 @@
 # gghighlight 0.1.0.9000
 
+* `gghighlight()` gets a new argument `unhighlighted_params`, which accepts a
+  list of parameters for the unhighlighted layer (e.g. `colour`, `fill`, `shape`,
+  and `size`). Accordingly, `unhighlighted_colour` is deprecated (#76).
+
 # gghighlight 0.1.0
 
 * Add `gghighlight()`, which replaces the current `gghighlight_line()` and `gghighlight_point()`; these functions are now deprecated.
diff --git a/R/gghighlight.R b/R/gghighlight.R
index a55be8e..b81757a 100644
--- a/R/gghighlight.R
+++ b/R/gghighlight.R
@@ -10,8 +10,8 @@
 #'   Number of layers to clone.
 #' @param max_highlight
 #'   Max number of series to highlight.
-#' @param unhighlighted_colour
-#'   Colour for unhighlighted geoms.
+#' @param unhighlighted_params
+#'   Aesthetics (e.g. colour, fill, and size) for unhighlighted geoms.
 #' @param use_group_by
 #'   If `TRUE`, use [dplyr::group_by()] to evaluate `predicate`.
 #' @param use_direct_label
@@ -20,6 +20,8 @@
 #'   Column name for `label` aesthetics.
 #' @param label_params
 #'   A list of parameters, which is passed to [ggrepel::geom_label_repel()].
+#' @param unhighlighted_colour
+#'   (Deprecated) Colour for unhighlighted geoms.
 #'
 #' @examples
 #' d <- data.frame(
@@ -42,11 +44,12 @@
 gghighlight <- function(...,
                         n = NULL,
                         max_highlight = 5L,
-                        unhighlighted_colour = ggplot2::alpha("grey", 0.7),
+                        unhighlighted_params = list(),
                         use_group_by = NULL,
                         use_direct_label = NULL,
                         label_key = NULL,
-                        label_params = list(fill = "white")) {
+                        label_params = list(fill = "white"),
+                        unhighlighted_colour = NULL) {
 
   # if use_direct_label is NULL, try to use direct labels but ignore failures
   # if use_direct_label is TRUE, use direct labels, otherwise stop()
@@ -57,12 +60,20 @@ gghighlight <- function(...,
     label_key_must_exist <- FALSE
   }
 
+  # if fill is not specified, use colour for fill, or vice versa
+  unhighlighted_params <- normalize_unhighlighted_params(unhighlighted_params)
+
+  if (!is.null(unhighlighted_colour)) {
+    rlang::warn("unhighlighted_colour is deprecated. Use unhighlighted_params instead.")
+    unhighlighted_params$colour <- unhighlighted_colour
+  }
+
   structure(
     list(
       predicates = rlang::enquos(...),
       n = n,
       max_highlight = max_highlight,
-      unhighlighted_colour = unhighlighted_colour,
+      unhighlighted_params = unhighlighted_params,
       use_group_by = use_group_by,
       use_direct_label = use_direct_label,
       label_key_must_exist = label_key_must_exist,
@@ -115,7 +126,7 @@ ggplot_add.gg_highlighter <- function(object, plot, object_name) {
     layers_bleached,
     group_infos,
     bleach_layer,
-    unhighlighted_colour = object$unhighlighted_colour
+    unhighlighted_params = object$unhighlighted_params
   )
 
   # Sieve the upper layer.
@@ -215,18 +226,20 @@ calculate_group_info <- function(data, mapping) {
   }
 }
 
-bleach_layer <- function(layer, group_info,
-                         unhighlighted_colour  = ggplot2::alpha("grey", 0.7)) {
-  # Set colour and fill to grey when it is included in the mappping.
-  # But, if the default_aes is NA, respect it.
-  # (Note that this needs to be executed before modifying the layer$mapping)
-  params_bleached <- purrr::map(
-    rlang::set_names(c("colour", "fill")),
-    choose_bleached_colour,
-    geom = layer$geom, mapping = layer$mapping, bleached_colour = unhighlighted_colour
-  )
-  params_bleached <- purrr::compact(params_bleached)
-  layer$aes_params <- utils::modifyList(layer$aes_params, params_bleached)
+bleach_layer <- function(layer, group_info, unhighlighted_params) {
+  # `colour` and `fill` are special in that they needs to be specified even when
+  # it is not included in unhighlighted_params. But, if the default_aes is NA,
+  # respect it (e.g. geom_bar()'s default colour is NA).
+  # Note that this depends on the mapping, so this needs to be done before modifying the mapping.
+  unhighlighted_params$colour <- unhighlighted_params$colour %||% get_default_aes_param("colour", layer$geom, layer$mapping)
+  unhighlighted_params$fill <- unhighlighted_params$fill %||% get_default_aes_param("fill", layer$geom, layer$mapping)
+
+  # c.f. https://github.com/tidyverse/ggplot2/blob/e9d4e5dd599b9f058cbe9230a6517f85f3587567/R/layer.r#L107-L108
+  aes_params_bleached <- unhighlighted_params[names(unhighlighted_params) %in% layer$geom$aesthetics()]
+  geom_params_bleached <- unhighlighted_params[names(unhighlighted_params) %in% layer$geom$parameters(TRUE)]
+
+  layer$aes_params <- utils::modifyList(layer$aes_params, aes_params_bleached)
+  layer$geom_params <- utils::modifyList(layer$geom_params, geom_params_bleached)
 
   # remove colour and fill from mapping
   layer$mapping[c("colour", "fill")] <- list(NULL)
@@ -252,17 +265,30 @@ bleach_layer <- function(layer, group_info,
   layer
 }
 
-choose_bleached_colour <- function(aes_name, geom, mapping, bleached_colour) {
-  if (!aes_name %in% geom$aesthetics()) {
+default_unhighlighted_params <- list(
+  colour = ggplot2::alpha("grey", 0.7),
+  fill = ggplot2::alpha("grey", 0.7)
+)
+
+get_default_aes_param <- function(aes_param_name, geom, mapping) {
+  # no default is available
+  if (!aes_param_name %in% names(default_unhighlighted_params)) {
     return(NULL)
   }
-  # if aes_name is specified in the mapping, it should be bleached.
-  if (!aes_name %in% names(mapping) &&
-      aes_name %in% names(geom$default_aes) &&
-      is.na(geom$default_aes[aes_name])) {
-    return(NA)
+
+  # if it is specified in mapping, it needs to be overriden
+  if (aes_param_name %in% names(mapping)) {
+    return(default_unhighlighted_params[[aes_param_name]])
   }
-  return(bleached_colour)
+
+  # if the geom has default value and is NA, use NA
+  if (aes_param_name %in% names(geom$default_aes) &&
+      is.na(geom$default_aes[[aes_param_name]])) {
+      return(NA)
+  }
+
+  # otherwise, use the default grey
+  default_unhighlighted_params[[aes_param_name]]
 }
 
 sieve_layer <- function(layer, group_info, predicates,
@@ -365,3 +391,17 @@ choose_col_for_filter_and_arrange <- function(data, exclude_col) {
     arrange = rlang::syms(names(data)[!col_idx_lgl & !col_idx_lst])
   )
 }
+
+normalize_unhighlighted_params <- function(aes_params) {
+  if (!is.list(aes_params)) {
+    rlang::abort("unhighlighted_params must be a list.")
+  }
+
+  # color is an alias of colour
+  if (!is.null(aes_params$color)) {
+    aes_params$colour <- aes_params$colour %||% aes_params$color
+    aes_params$color <- NULL
+  }
+
+  aes_params
+}
diff --git a/man/gghighlight-old.Rd b/man/gghighlight-old.Rd
index 1d8d12e..3e5da21 100644
--- a/man/gghighlight-old.Rd
+++ b/man/gghighlight-old.Rd
@@ -7,14 +7,14 @@
 \title{Highlight Data With Predicate}
 \usage{
 gghighlight_line(data, mapping, predicate, max_highlight = 5L,
-  unhighlighted_colour = ggplot2::alpha("grey", 0.7), use_group_by = TRUE,
-  use_direct_label = TRUE, label_key = NULL, ...,
-  environment = parent.frame())
+  unhighlighted_colour = ggplot2::alpha("grey", 0.7),
+  use_group_by = TRUE, use_direct_label = TRUE, label_key = NULL,
+  ..., environment = parent.frame())
 
 gghighlight_point(data, mapping, predicate, max_highlight = 5L,
-  unhighlighted_colour = ggplot2::alpha("grey", 0.7), use_group_by = FALSE,
-  use_direct_label = TRUE, label_key = NULL, ...,
-  environment = parent.frame())
+  unhighlighted_colour = ggplot2::alpha("grey", 0.7),
+  use_group_by = FALSE, use_direct_label = TRUE, label_key = NULL,
+  ..., environment = parent.frame())
 }
 \arguments{
 \item{data}{Default dataset to use for plot. If not already a data.frame,
diff --git a/man/gghighlight.Rd b/man/gghighlight.Rd
index a171878..f8917c3 100644
--- a/man/gghighlight.Rd
+++ b/man/gghighlight.Rd
@@ -5,9 +5,9 @@
 \title{Highlight Data With Predicate}
 \usage{
 gghighlight(..., n = NULL, max_highlight = 5L,
-  unhighlighted_colour = ggplot2::alpha("grey", 0.7), use_group_by = NULL,
-  use_direct_label = NULL, label_key = NULL, label_params = list(fill =
-  "white"))
+  unhighlighted_params = list(), use_group_by = NULL,
+  use_direct_label = NULL, label_key = NULL, label_params = list(fill
+  = "white"), unhighlighted_colour = NULL)
 }
 \arguments{
 \item{...}{Expressions to filter data, which is passed to \code{\link[dplyr:filter]{dplyr::filter()}}.}
@@ -16,7 +16,7 @@ gghighlight(..., n = NULL, max_highlight = 5L,
 
 \item{max_highlight}{Max number of series to highlight.}
 
-\item{unhighlighted_colour}{Colour for unhighlighted geoms.}
+\item{unhighlighted_params}{Aesthetics (e.g. colour, fill, and size) for unhighlighted geoms.}
 
 \item{use_group_by}{If \code{TRUE}, use \code{\link[dplyr:group_by]{dplyr::group_by()}} to evaluate \code{predicate}.}
 
@@ -25,6 +25,8 @@ gghighlight(..., n = NULL, max_highlight = 5L,
 \item{label_key}{Column name for \code{label} aesthetics.}
 
 \item{label_params}{A list of parameters, which is passed to \code{\link[ggrepel:geom_label_repel]{ggrepel::geom_label_repel()}}.}
+
+\item{unhighlighted_colour}{(Deprecated) Colour for unhighlighted geoms.}
 }
 \description{
 \code{gghiglight()} highlights (almost) any geoms according to the given predicates.
diff --git a/tests/testthat/test-gghighlight.R b/tests/testthat/test-gghighlight.R
index ba28a7e..0677e96 100644
--- a/tests/testthat/test-gghighlight.R
+++ b/tests/testthat/test-gghighlight.R
@@ -20,7 +20,7 @@ g_info <- list(data = d_, id = ids, key = aes(colour = type))
 
 expect_equal_layer <- function(x, y) {
   x$mapping <- x$mapping[sort(names(x$mapping))]
-  y$mapping <- x$mapping[sort(names(y$mapping))]
+  y$mapping <- y$mapping[sort(names(y$mapping))]
   expect_equal(x, y)
 }
 
@@ -88,31 +88,49 @@ aes_bleached <- aes_string(x = paste0(prefix, 1),
 
 test_that("bleach_layer() works", {
   # If colour is specified, colour is used as the group key.
-  expect_equal_layer(bleach_layer(geom_line(aes(colour = type), d), g_info, grey07),
+  expect_equal_layer(bleach_layer(geom_line(aes(colour = type), d), g_info, list()),
                      geom_line(aes_bleached, d_bleached, colour = grey07))
 
   # If colour is specified but group_key is NULL, the result is the same data.
-  expect_equal_layer(bleach_layer(geom_line(aes(colour = type), d), NULL, grey07),
+  expect_equal_layer(bleach_layer(geom_line(aes(colour = type), d), NULL, list()),
                      geom_line(aes(colour = NULL, fill = NULL), d, colour = grey07))
 
   # If the geom accepts fill, it is sets to grey even when it is not included in the mapping.
-  expect_equal_layer(bleach_layer(geom_bar(aes(colour = type), d), g_info, grey07),
-                     geom_bar(aes_bleached, d_bleached, colour = grey07, fill = grey07))
+  expect_equal_layer(bleach_layer(geom_col(aes(colour = type), d), g_info, list()),
+                     geom_col(aes_bleached, d_bleached, colour = grey07, fill = grey07))
 
   # If the default of colour of the geom is NA and mapping doesn't specify it, params will be NA.
-  expect_equal_layer(bleach_layer(geom_bar(aes(fill = type), d), g_info, grey07),
-                     geom_bar(aes_bleached, d_bleached, colour = NA, fill = grey07))
+  expect_equal_layer(bleach_layer(geom_col(aes(fill = type), d), g_info, list()),
+                     geom_col(aes_bleached, d_bleached, colour = NA, fill = grey07))
 
   # If colour and fill is specified at the same time, fill is used as the group key.
-  expect_equal_layer(bleach_layer(geom_bar(aes(colour = type, fill = type), d), g_info, grey07),
-                     geom_bar(aes_bleached, d_bleached, colour = grey07, fill = grey07))
+  expect_equal_layer(bleach_layer(geom_col(aes(colour = type, fill = type), d), g_info, list()),
+                     geom_col(aes_bleached, d_bleached, colour = grey07, fill = grey07))
 
   # If mapping doesn't have colour or fill, group or x aes can be used as group key.
   # c.f. https://github.com/yutannihilation/gghighlight/pull/17#issuecomment-390486101.
-  expect_equal_layer(bleach_layer(geom_bar(aes(group = type), d), g_info, grey07),
-                     geom_bar(aes_bleached, d_bleached, colour = NA, fill = grey07))
-  expect_equal_layer(bleach_layer(geom_bar(aes(x = type), d), g_info, grey07),
-                     geom_bar(aes_bleached, d_bleached, colour = NA, fill = grey07))
+  expect_equal_layer(bleach_layer(geom_col(aes(group = type), d), g_info, list()),
+                     geom_col(aes_bleached, d_bleached, colour = NA, fill = grey07))
+  expect_equal_layer(bleach_layer(geom_col(aes(x = type), d), g_info, list()),
+                     geom_col(aes_bleached, d_bleached, colour = NA, fill = grey07))
+
+  # unhighlighted_params can be more detailed
+  expect_equal_layer(bleach_layer(geom_line(aes(colour = type), d), g_info,
+                                  list(colour = "blue", size = 3)),
+                     geom_line(aes_bleached, d_bleached, colour = "blue", size = 3))
+
+  expect_equal_layer(bleach_layer(geom_col(aes(colour = type, fill = type), d), g_info,
+                                  list(colour = "blue", width = 0.5)),
+                     geom_col(aes_bleached, d_bleached, colour = "blue", fill = grey07, width = 0.5))
+
+  expect_equal_layer(bleach_layer(geom_col(aes(fill = type), d), g_info,
+                                  list(fill = "blue", width = 0.5)),
+                     # TODO: the order of fill and colour matters here...
+                     geom_col(aes_bleached, d_bleached, fill = "blue", colour = NA, width = 0.5))
+
+  expect_equal_layer(bleach_layer(geom_col(aes(colour = type, fill = type), d), g_info,
+                                  list(colour = ggplot2::alpha("grey", 0.9), fill = grey07, width = 0.5)),
+                     geom_col(aes_bleached, d_bleached, colour = ggplot2::alpha("grey", 0.9), fill = grey07, width = 0.5))
 })
 
 test_that("sieve_layer() works with simple cases", {
diff --git a/tests/testthat/test-internals.R b/tests/testthat/test-internals.R
index 150550f..bb67e91 100644
--- a/tests/testthat/test-internals.R
+++ b/tests/testthat/test-internals.R
@@ -15,3 +15,22 @@ test_that("choose_col_for_filter_and_arrange() works", {
   expect_equal(choose_col_for_filter_and_arrange(d1, rlang::quo(x)),
                !!expected)
 })
+
+test_that("normalize_unhighlighted_params() works", {
+  expect_listequal <- function(x, y) {
+    expect_equal(!!x[sort(names(x))], !!y[sort(names(y))])
+  }
+
+  # if fill and colour is specified, respect both
+  expect_listequal(normalize_unhighlighted_params(list(colour = "blue", fill = "red")),
+                   list(colour = "blue", fill = "red"))
+  # other parameters are left as is
+  expect_listequal(normalize_unhighlighted_params(list(fill = "red", size = 0.2)),
+                   list(fill = "red", size = 0.2))
+  # color is an alias of colour
+  expect_listequal(normalize_unhighlighted_params(list(color = "red")),
+                   list(colour = "red"))
+  # if both colour and color are specified, use colour.
+  expect_listequal(normalize_unhighlighted_params(list(colour = "blue", color = "red")),
+                   list(colour = "blue"))
+})