This should fit the bill. Sounds like a super-annoying thing to have going on, but there you have it:
@echo off
set NUM=0 1 2 3 4 5 6 7 8 9 A B C D E F
for %%x in (%NUM%) do (
for %%y in (%NUM%) do (
color %%x%%y
timeout 1 >nul
)
)