I haven't used Numbers but I would say "Probably not."
Spreadsheets don't generally expose their presentation layer (font styles, colors, etc.) readily to their calculation layer (cell formulas and inbuilt functions).
A common approach to your task is to use another column to store a status for each payment (Due, Paid, etc.) and then to use a conditional summation function to correctly sum the total. The Excel function is SUMIF and I'd expect Numbers to have something similar.