Don't the letter have to be capitalized? Also, Here is a list of ones I commonly use
Black: 000000
Blue: 0000FF
Red: FF0000
Green: 00FF00
White: FFFFFF
Dull Green: 008000
Yellow: FFFF00
Purple: 800080
Orange: FFA500
Hot Pink: EEA2EE
Gold: FFD700
Silver: C0C0C0
Light Gray: A0A0A0
Gray: 808080
Dark Gray: 606060
Pink: FFC0CB
Magenta: FF00FF
Cyan: 00FFFF