Returns the value of ColourList attribute. This attribute represents a list of colours defined by the red, green, blue components. All values are provided as a ratio of 0.0 ≤ value ≤ 1.0. When using 8bit for each colour channel, a value of 0.0 equals 0, a value of 1.0 equals 255, and values between are interpolated.

Returns the value of ColourList attribute.