Excel, how to add/detect a coloured cell as only number "1" and ignore the cell value

Hey, ive got a attendance report with up to 10 weeks per person. Right now i have 2 sepertae formulas, 1 which uses cell value to determine colour (so 1=red (absent), 2=green (present) etc.) And another formula that uses the "total weeks present" ('4/10) to determine a percentage (=40%). Is there any way i can get the "total weeks present" to increase by 1 (from'4/10 to '5/10) when i fill in the cell with present (2) and not increase the "total weeks present" by 2 (almost ignoring the cell value, but detecting the cell is full or something like that)?

Thanks in advance!