Well I guess I'm in the minority here, but I think that there already enough frogs on the panel and if the colors of the art and TB are close but wrong they will look wrong. The only way I would think the green ball w/frog option was good would be if you were going to get the ball first and then match the CP green to it. I'm alone in this opinion so far, but it's my opinion none-the-less.
Either one will look good, but if the colors don't match then black is better.