The general fuzziness and lack of detail in these photos is mostly due to being lit primarily by one strong color.

Your camera's sensor has what is called a Bayer color filter array on it which allows it to record only one primary color per sensor element. In your camera or raw processing software, the single-color-per-pixel sensor data is combined to produce a full-color image.

Important to your situation is the fact that for each set of four sensor elements, two are green-sensitive, one is red-sensitive, and one is blue-sensitive.

Knowing that, it's easy to see that when your subject is lit only by strong red light, you're only recording image data with 1/4 of the sensor elements on your sensor. The remaining 3/4 of the data has to be interpolated and most interpolation algorithms aren't going to do well without any green- or blue-channel information. That results in a blurry image lacking in fine detail.

Unfortunately there's no good way around this with traditional color-filter-array sensors. A Foveon sensor would excel in situations like this, as all its sensor elements are sensitive to all colors. Color film would also not suffer this problem.

It's also worth noting that this is a very good reason not to use color contrast filters (intended for black-and-white film) on a digital camera.