Excel 2007
You will get the wrong light/dark shades
for aqua and yellow if you choose
RGB 0,255,255 and 255,255,0 respectively.
Try 20,235,252 and 250, 255,0 instead.
Page Layout Colors Custom_ Edit Accent1
More Colors Custom RGB.
Pure magenta, red, green and blue are OK.
For other non-primary colors, it's trial and error.