Never had a dream where you remember colours, just have memories of dreamed events the next day. I would doubt, however, the possibility of seeing new colours in dreams since dreams are based on things you already know and go from there with imagination.

BTW running a red light is NOT an excuse if the red-yellow-green lights are in specific positions (e.g. here, red is on top, yellow middle, green lower).

I can usually see the red, but occasionally, with certain lighting conditions, the red looks like a yellow to me. That's when I look at position of the lights to make sure I know what to do.

In my experience, I know all the colours, it is just when they are similar in hues that I have trouble - e.g. yellow and pale lime green. The only way for me to recognize if a sample colour was one or the other would be to compare it to a sample of yellow. That way I can notice the minute hue differences and tell which is which, usually (but not always) without much trouble. Many people have it worse though.