Coloured buttons in the editor

To the left of the current tileset shown in the editor, there is a vertical row of colored squares that seem to remain the same whichever tileset is selected. I still haven't figured out what it is used for!

Can someone please enlighten me?

[mod]Changed topic title. See the Official Forum Rules about non-descriptive titles[/mod]

It changes the background color of the tileset

Specifically, click on one of the squares and it changes the color shown behind the tileset.  Generally not useful, unless you have tiles that look extremely similar to that background for some reason.

The reason for these button is the usage with transparant tiles. Sometimes you have a tileset that only has say... blue lines, and for the rest its transparant. If the background color has that same color it will be nearly invisible in the editor. Selecting a different background color can give you the visibility back. It is also nice to see how a certain tile looks on a different background so you can use this in your level design.