I find that it's a difficult thing to find the right color and
gobo choices sometimes because, like you said, you have to find the "right red" from all of the choices available. But if you really look at the colors, you'll find that they are all different from each other, and that difference is critical. In your scenario, if the red that you choose is say, slightly too pink, then the angry mood might not completely be conveyed. What I like to do is narrow down to 3 or 4 colors that I'm trying to pick from and then work from there by comparing them directly. The best resource is
Rosco's color booklet and/or the website to see what they recommend and what other designers have used in the past. Also, pay attention to the transmission % on the
swatchbook. Some colors are very deceiving in that they don't look that saturated, yet have a transmission % of like 14%, which depending on the application could be a problem.
Another thing to consider. So if you want an "angry" red, then you have to consider both the way that the color itself looks and works to convey that angry feeling, and how it works with the other colors that you have. For example, if you have 2 systems of light from the same angle, a warm and cool, then you want to pick colors that look nice when mixed together.