Interestingly on p.21 of the second the manual where the paint formulas are described, it lists a standard code and number for the black paint: 'U.S. Army Standard W.D. 15 - No. 4 Black'. But not for the yellow, green & cream.
However a quick search leads me to the 'Papers On Paint And Varnish And Their Materials Used In Manufacture', p.422-424 (https://archive.org/details/papersonpaintan01gardgoog) and this does list the code and number for the other colors: 'Camouflage Colors U.S. Army Standard W.D. 14 - No. 1 Yellow/No. 2 Green/No. 3 Cream', amongst dozens of other paints (no mauve or brown though).
Just thought it was interesting to see the standard and numbering of these paints & colors.