VB.Net Graphics Question DrawPie

Hi using the graphics objects I managed to a draw a pie segment on the screen.

I'm now stuck because when I hover over the pie segment I need to display some text. Any ideas?

I have tried many things, I even tried to get the pixel color at a mouse point so that I could compare that colour with the colour I painted the segment with. But at the moment I battling to even get the colour from a pixel.