Chat Text Color

Here's a question for all of you. Let's see if anyone has the answer. I have a SRCDS running Half-Life 2 Deathmatch. I want to change the color of the text that get's displayed when a client playing the game types something into his/her "CHAT" box then hits enter. You know, something like "HELLO EVERYONE" or "HEY, I LIKE THIS MAP" or anything else. The server has it's default color of yellow for the chat text, but I want to change only the chat text color to green, and leave the others in yellow. Any ideas on how to do it? What file to modify? And what would be the color code for green?

Thanks!!