Please help!

[Wren]

I'm absolutely desperate! I have looked everywhere on the NET, in books, asked everyone I know to help identify this snake, and no one knows. Can someone here help?

I was in central Texas next to a creek. There was a lovely snake, about 12" long, smooth, slender, green head, red tongue, bright well-defined red stripe from neck to tail. There was a very thin green line down the sides of the red stripe...very thin! The rest of the snake was "snake yellow". I would be SO happy to find out what this could have been! Can someone here take a guess please?

THANK YOU!
THANK YOU!
THANK YOU!