diff --git a/sksurgerybard/visualisation/bard_visualisation.py b/sksurgerybard/visualisation/bard_visualisation.py
index adb2d98..bf1c787 100644
--- a/sksurgerybard/visualisation/bard_visualisation.py
+++ b/sksurgerybard/visualisation/bard_visualisation.py
@@ -4,6 +4,7 @@
 
 import numpy as np
 from sksurgeryvtk.models.vtk_sphere_model import VTKSphereModel
+from sksurgerybard.visualisation.colours import get_yellow, get_green
 
 def configure_model_and_ref(configuration, transform_manager):
     """
diff --git a/sksurgerybard/visualisation/colours.py b/sksurgerybard/visualisation/colours.py
index 3fa5a43..c2ccc0c 100644
--- a/sksurgerybard/visualisation/colours.py
+++ b/sksurgerybard/visualisation/colours.py
@@ -6,42 +6,78 @@
 # Grayscale Design palette: https://grayscale.design/app?lums=100.00,88.89,77.78,66.67,55.56,44.44,33.33,22.22,11.11,0.00&palettes=%23ffff00,%2300ff00&filters=0%7C0,0%7C0&names=Yellow,Greeen&labels=,
 
 #lets create dictionaries we can use of pre set colours
-{
-  "grayscale": {
-    "50": "rgb(255, 255, 255)",
-    "100": "rgb(242, 242, 242)",
-    "200": "rgb(228, 228, 228)",
-    "300": "rgb(213, 213, 213)",
-    "400": "rgb(197, 197, 197)",
-    "500": "rgb(178, 178, 178)",
-    "600": "rgb(156, 156, 156)",
-    "700": "rgb(130, 130, 130)",
-    "800": "rgb(94, 94, 94)",
-    "900": "rgb(0, 0, 0)"
-  },
-  "Yellow": {
-    "50": "rgb(255, 255, 255)",
-    "100": "rgb(250, 250, 0)",
-    "200": "rgb(236, 236, 0)",
-    "300": "rgb(220, 220, 0)",
-    "400": "rgb(203, 203, 0)",
-    "500": "rgb(184, 184, 0)",
-    "600": "rgb(162, 162, 0)",
-    "700": "rgb(134, 134, 0)",
-    "800": "rgb(97, 97, 0)",
-    "900": "rgb(0, 0, 0)"
-  },
-  "Greeen": {
-    "50": "rgb(255, 255, 255)",
-    "100": "rgb(205, 255, 205)",
-    "200": "rgb(129, 255, 129)",
-    "300": "rgb(0, 247, 0)",
-    "400": "rgb(0, 228, 0)",
-    "500": "rgb(0, 207, 0)",
-    "600": "rgb(0, 182, 0)",
-    "700": "rgb(0, 151, 0)",
-    "800": "rgb(0, 110, 0)",
-    "900": "rgb(0, 0, 0)"
-  }
+grayscale = {
+    "50": [255, 255, 255],
+    "100": [242, 242, 242],
+    "200": [228, 228, 228],
+    "300": [213, 213, 213],
+    "400": [197, 197, 197],
+    "500": [178, 178, 178],
+    "600": [156, 156, 156],
+    "700": [130, 130, 130],
+    "800": [94, 94, 94],
+    "900": [0, 0, 0]
 }
 
+yellow = {
+    "50": [255, 255, 255],
+    "100": [250, 250, 0],
+    "200": [236, 236, 0],
+    "300": [220, 220, 0],
+    "400": [203, 203, 0],
+    "500": [184, 184, 0],
+    "600": [162, 162, 0],
+    "700": [134, 134, 0],
+    "800": [97, 97, 0],
+    "900": [0, 0, 0]
+}
+
+green =  {
+    "50": [255, 255, 255],
+    "100": [205, 255, 205],
+    "200": [129, 255, 129],
+    "300": [0, 247, 0],
+    "400": [0, 228, 0],
+    "500": [0, 207, 0],
+    "600": [0, 182, 0],
+    "700": [0, 151, 0],
+    "800": [0, 110, 0],
+    "900": [0, 0, 0]
+}
+
+def y_pos_to_luminance(y_pos):
+    """
+    y_pos is a float between 0 and 1 representing the position of the 
+    mouse on the screen. High y_pos corresponds to high luminance (50)
+    low y_pos to low luminance (900)
+    """
+    luminances = ["50", "100", "200", "300", "400", "500", "600",
+            "700", "800", "900"]
+    index = 0
+    threshold = 0.9
+    while index < len(luminances):
+        if y_pos > threshold:
+            return luminances[index]
+        index += 1
+        threshold -= 0.1
+
+    return luminances[index-1]
+
+
+def integer_colour_to_float(colour):
+    """
+    converts an integer colour to a float colour
+    """
+    out=[]
+    for value in colour:
+        out.append((value)/256.0)
+
+    return out
+
+
+
+def get_green(y_pos):
+    return green.get(y_pos_to_luminance(y_pos))
+
+def get_yellow(y_pos):
+    return integer_colour_to_float(yellow.get(y_pos_to_luminance(y_pos)))
diff --git a/tests/visualisation/test_colours.py b/tests/visualisation/test_colours.py
new file mode 100644
index 0000000..df5513a
--- /dev/null
+++ b/tests/visualisation/test_colours.py
@@ -0,0 +1,38 @@
+#  -*- coding: utf-8 -*-
+"""Tests for BARD pointer module"""
+import pytest
+import vtk
+import numpy as np
+from sksurgerycore.transforms.transform_manager import TransformManager
+import sksurgerybard.visualisation.colours as cls
+
+#pylint:disable=no-member
+
+def test_y_pos_to_luminance():
+    """Checks that the y_pos to luminance look up works"""
+
+    assert cls.y_pos_to_luminance(1.0) == "50"
+    assert cls.y_pos_to_luminance(0.91) == "50"
+    assert cls.y_pos_to_luminance(0.90) == "100"
+    assert cls.y_pos_to_luminance(0.80) == "200"
+    assert cls.y_pos_to_luminance(0.70) == "300"
+    assert cls.y_pos_to_luminance(0.60) == "400"
+    assert cls.y_pos_to_luminance(0.50) == "500"
+    assert cls.y_pos_to_luminance(0.40) == "600"
+    assert cls.y_pos_to_luminance(0.30) == "700"
+    assert cls.y_pos_to_luminance(0.20) == "800"
+    assert cls.y_pos_to_luminance(0.10) == "900"
+    assert cls.y_pos_to_luminance(0.00) == "900"
+
+
+def test_integer_colour_to_float():
+    """Tests that integer to float colour works"""
+    assert cls.integer_colour_to_float([255,128,0]) == [1.0, 0.5, 0.0]
+
+def test_get_yellow():
+    """Checks that get yellow returns the right value"""
+    assert cls.get_yellow(1.0) == [1.0, 1.0, 1.0]
+
+def test_get_green():
+    """Checks that get green returns the right value"""
+    assert cls.get_green(1.0) == [1.0, 1.0, 1.0]