I'm going to make some assumptions here.

A1=10
B1=20

So to get the percentage, in C1 type "=A1/B1" and then click the %
button on formatting toolbar at the top of the page.

To get the cell to change colour, have a look at
http://www.excelforum.com/showthread.php?t=560169


--
MartinShort

Software Tester & Musician
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