Teen Titans character designer Derrick Wyatt revealed some unused character designs at his blog: "Here are some Teen Titans designs I did for fun based on Adam Warren's "Titans: Scissors, Paper, Stone" comic. I had hoped at one point that we could use them in the show sometime. There was some discussion of it, but ultimately it didn't happen."
check out the designs and more at Derrick's blog
It's a shame they never appeared! they look verra cool.
For more on the Titans: Scissors, Paper, Stone, see their page