simultaneous (multi) color and size tracking

dear all,

i apologize as it's very likely that this issue has been addressed before, yet i could not find information in the forum that was specific enough for what i need.

a scenario: transparent Plexiglas table and a camera mounted right underneath, facing the table's surface from below. i'm taking plastic rectangle shapes of say four different colors and sizes, and place them one after the other on the table.

i would like to track in any given moment: which colors are present on the table, and whats the surface size of each.

can jitter do this at all with its core objects? is there any recommended external color/object detection library i should use to achieve this?

will appreciate any advise!

regards,
K.