This is a snip of the default colorset. As you can see it's the bold column of the colorset (the 2nd one fyi).
You can have a bunch of columns, I'm not sure how many.

The first 3 groups of numbers are the RGB colorcodes, I assume you know what they are and what they do.
The fourth one is the transparency of the color, the lower the more transparent. With 255 being the highest it's the most ''solid''.
DIV is just the name of the column.