Categories Dressing

[gjh42]

If there is a method you can use to distinguish between subcats you want in different colors, you can replace the selection code ($box_categories_array[$i]['path'] == 'cPath=3_42') with that.
I can't be any more specific without knowing exactly how you want to change colors.

You say "1000 products", but how many subcats do you have?
You don't need to specify every subcat; make a spec that covers them generally, and then specify the exceptions with the code above...