If you're not sure whether cooked quinoa is bad, there are a few things you can look for. First, check the color. If it's discolored or has changed color from when you cooked it, that's a bad sign. Cooked quinoa should be a light, pale color. Also, check the texture. If it's mushy or has changed texture from when you cooked it, that's another bad sign. Finally, smell it. If it smells bad, it probably is bad. If you're still not sure, err on the side of caution and throw it out.