Color- Synchronization between html and gd library

Is there any differences in color codes in php-gd library and html? When I pick a color and send it to script, it doesn't look same. I need to find out a procedure to make them synchronized.

Oh, I got a point, ##F0F8FF is a hexa-decimal representation of color, which is widely used in html and supported by all browsers. But, I should use different format of color code except hex which is similar to gd library's way of color recognition. Usually GD makes color from intensity of green, red and blue. I can also use this same format for html by using rgb($red, $green, $blue) instead of hex. Hope, it will help me.

Now, I have to think about dynamic use of this format which will come directly from my database. I think, if I use '-' as delimiter then it will be perfect. I will generate html and gd script from the same think as they require by deleting '-' and using the real values.

This way I could solve my problem.