i know how to make the pictures, but the colours?

Submit the following colors:

Page Background Color

Page Text Color
(This color is not used in the default templates, but it can be useful for achieving specific effects with customized templates.)

Table Border Color:

Category Strip Background Color

Category Strip Font Color

Table Heading Background Color

Table Heading Text Color

First Alternating Table Background Color
(These two 'alternating' colors are used alternately in long lists so that one row can easily be told from the next.)

Second Alternating Table Background Color

Link Color

Hover Color for Links

Time Color
(This color is used for the time field on the main forum summary page and the forum pages)

However, not all themes will be accepted, naturally :P

how do i submit them? using HTML #code?

Submit them in a Private Message to one of us (FQuist, Myself (Nebula), or another admin). We'll look it over, and tell you what we think, and if we'll post or not.

Also, just submit the piccys and the colors. There are many templates, so you don't worry about modifying HTML.