An ColorMatrix is a 4x4 color matrix that transforms the 4 color channels
with a 1x4 matrix that post-translates those 4 channels.
For example, the following is the layout with the scale (S) and post-transform
(PT) items indicated.
RS, 0, 0, 0 | RPT
0, GS, 0, 0 | GPT
0, 0, BS, 0 | BPT
0, 0, 0, AS | APT
An ColorMatrix is a 4x4 color matrix that transforms the 4 color channels with a 1x4 matrix that post-translates those 4 channels. For example, the following is the layout with the scale (S) and post-transform (PT) items indicated. RS, 0, 0, 0 | RPT 0, GS, 0, 0 | GPT 0, 0, BS, 0 | BPT 0, 0, 0, AS | APT