How's this for a wacky theory to explain Colin Steven's information:
6th Div. is red (1st Div.) over blue (2nd Div.)
7th Div. is grey (3rd Div.) over green (4th Div.)
then, just maybe, following the pattern without duplicating colours:
8th Div. is maroon (5th Div.) over LIGHT GREEN, a non divisional colour (it's shown as a different green than the one used for the 4th Div.), perhaps introduced for the purpose. Over time, the light green was replaced with the standard green.
It seems Bill's answer should be correct, but it also seems information on how to wear the 8th Div. flash is always confused, perhaps for some reason???