Can a photodiode be used to differentiate between colors on a computer screen?

Question

Even if it can differentiate between just 2 colors wud be sufficient. I need to capture data from a monitor using photodiodes for processing in an 8051 microcontroller. Any other suggestion for data stream capture wud be greatly appreciated. And please specify any special photodiodes if used.

Answer 1

Yes, NO and Maybe.

On it's Own . NO
With a set of Red Green and Blue, filters, YES.

If you had a set of revolving filters in front of lens, and could tell what colour lens was in place, it would be able to tell if it was emiting light of that colour.
Then is it detects on Blue and Green, there is yellow light displayed. etc etc etc

Or if you used 3 diodes with a filter each,

Also remember to know what area you need to read . . . a photodiode without an accurate lens system cannot read accurate areas.

Answer 2

if you used 2 diodes and gave 1 a red filter and one a green filter, that would do the job. Then a simple OR will decide for you.