TexasCHLforum.com

Although the law doesn't always follow good common sense, it would be ridiculous if it was illegal to enter an intersection on a yellow whether or not the light turns red while you are still in the intersection or not. Say you're driving 45 in a 45 or even 40 in a 45 and you are 10 feet from the stop line when the light turns yellow. You couldn't possibly be expected to stop in time, thus the "stop on yellow if you can safely do so," which in this case, you couldn't. I see no reason why you should have been ticketed there if it was yellow as you passed the stop line, and I would absolutely fight it.