1. Proportionality between RGB colors
Applying proportionality between two RGB codes gives the following expression:
The RGB final can be written as:
The expression:
(A) Is valid when the colors are within the same hue range and are equal in saturation (with few Exceptions).
(B) Predicts the RGB code for vertical changes.
​
RGB = 255 If:
Product ≥ 255
To ignore the RGB order:
The expression is written in terms such as maximum, intermediate and minimum.
Exceptions:
Predicts vertical changes even if Hue is changed.
Errors (RGB max): Counts correctly only when saturation is between 0% and 75%. The errors are reduced by using other parameters such as IM.
2. Brightness
The brightness has a value between 0 and 1 and changes vertically and is equal to RGB max (M).
The expression is valid when the colors are within the same hue range and are equal in saturation.
Brightness remains constant horizontally:
The following expression can be written via the uniformity principle:
