Clear
..and I like those chewy dog treats.
But here's something more useful, I hope:
http://www.chess.com/forum/view/chess-equipment/chess-clocks3
I like this one a lot:
http://www.amchesseq.com/40sacogacl.html
it's very cheap, sturdy, has plenty of good options and it has a well desiged light-button combination.