My son knows his colors pretty well, but still frequently seems to say "blue" for red items, and "red" for blue items (although it seems more common for him to call something red blue than the other way around).
We have a color matching game where a spinner points to a color, and you discard a card with a balloon matching that color. I noticed that he had no problem matching the color on the spinner with the color of the card he was discarding, but he did call the red card blue.
When I correct him, he usually says "oh, yeah," and then starts referring to it by the right color.
Similarly, he'll sometimes ask for his favorite car by saying the blue car, even though it is fire-engine red.
Are these signs that he might be color-blind? I know that this is a fairly common thing, especially in males (I believe somewhere around 10% of men have some degree of color-blindness), so I'm not going to make a special trip to the doctor about it (although I'll mention it at our next scheduled wellness visit), but I'd like to know if I can find out on my own.
Is confusion between red and blue normal for color-blindness? Is there a way that I can test this and eliminate the possibility that he's just getting the words confused?