The problem is when the board looks just like another, it is easy to confuse what game you are playing. All other Chess variants which look the same as regular chess but have very different rules are a different color except for 1 - Extinction chess. (which of course the easiest solution is to give it a different border.)

Berolina - redish border
Knight Relay - Dark Green border
Legan - Bluish border
3 checks - light green
Cylinder - greenish
Amazon Chess - Green
Ambiguoues - Blue
Atomic - Dark Blue
Loop - Light Blue
Anti - Red

All the rest either play just like chess (Crazy screen), or have a completly different setup (Maharajah) that you don't need a border since it is easy to tell you are playing a different game.

Extinction Chess looks just like regular chess, but you can't play it like regular chess - you have to play it differently, yet it does not have a different border color.

And it's not about memorizing the colors - seeing a different color for me at least quickly tells me there is something special about the game, which then leads me to look at the game name.

Heck - if it is such a big deal that this one game does not have a color - then lets get rid of the colors for all the Chess games. Of course I'll stop playing those also.