The tables for the True Slaad are up. Play around until I post the stat block.
Roll once for dominant color and once for gender.
Lesser True Slaad: 2 minor, 1 medium variation.
True Slaad: 3 minor, 2 medium, 1 major variation.
Greater True Slaad: 4 minor, 3 medium, 2 major variations.
Edit: The power of chaos is spoooky. I rolled up an orange FSR True Slaad with both Narrow Jaw and Bisected Jaw... the major trait came out to be the extra mouth.