Changing a Background of a children(Rectangle) in a wrap panel

Hi

i am using a wrap panel whose width is some 1000 and height is 1000. i am filling the wrap panel with 100 rectangle

size of 100 (Width and Height).

My Question is: can i change the color of a individual rectangle in a wrap panel.

like : 3 row 2 column rectangle color to blue

or

50'th rectangle to pink

- is there any panel which should have the functionality of wrappanel

Thank you