Can it change pie slice color code behind?

Hello, I want to use doughnut chart in crystal report as below.

I built some color highlight mappings in chart expert. But it must give a fixed value in item editor when build mapping:

top1(use item value = 'fund1' instead temporarily) ->custom color 1

top2(use item value = 'fund2' instead temporarily) ->custom color 2

top3(use item value = 'fund3' instead temporarily) ->custom color 3

....

I use some temp values instead when building mappings, because I don't know the real values before rendering(set display top N only), and plan to update the temp values with real ones code behind after rendering. Is it possible?

I also have another solution to try it.

I don't build any color highlight mapping before rendering, and update the mapping colors for top N with expected custom colors after rendering. Is it possible?

Thank you.