Normal for tracks to be going into the red?

Just be listening to other people final mixes in Sonar and found some of their tracks are constantly in the red.
I always thought this was a bad thing but the sound they have is really good despite the db going into the red.

So tracks going into the red are a non issue?

"Red" can carry very different meanings in different applications' meters. In SONAR's meters, the red region starts at -6db. It indicates "look out, you may be getting too hot", but does not necessarily indicate distortion. Mastered mixes typically stay "in the red" most of the time during playback. That's normal.

Just don't confuse this with what you're trying to avoid during recording and mixing, which is something quite different. In that case, what you have to look at are absolute decibel values, regardless of what color the meter is. While going over 0db is a definite no-no, you may have other target maximums to shoot for depending on what happens to your mix next (e.g. sent out for mastering, burn to CD, encode to MP3).