Convert RGB to HSV

[Colin Holgate]

Your current version has a slight problem in that if you are over some  
of the text at the time you click, the mouseColor will be based on the  
text color, or the antialiased colors that appear at the edge of  
letters. Another approach you could take would be to have a one pixel  
big field (with its backgroundcolor set to the desired value) that you  
place under the mouse location just before taking the mouseColor.