Overview

Not all browsers are able to read an attribute like "GREEN" or "LightGrey". Some browsers (especially older ones) don't recognize the colornames. To make your colors visible to as many as possible, you should make it a rule allways to use the HEX-CODES of the colors. Every color have a HEX-CODE to identify itself. All HEX-CODES starts with this sign: "#" followed by 3 pairs of siffers

To make a word in the color YELLOW you can use this line:
<FONT COLOR="YELLOW">YELLOW</FONT>

But if you want your yellow color to show up in the rest of the browsers, you should change the word YELLOW to it's respective HEX-Code. The HEX-Code equal to YELLOW is: #FFFF80. So your line should look like this:
<FONT COLOR="#FFFF80">YELLOW</FONT>