Later in Spring (May) the wildflowers in Red Rock canyon can be gorgeous. Pics are on my other computer, or I'd post one.
Also in Red Rocks take in the smaller side canyons. Red Rock "canyon" is really a big washed out horseshoe shaped bowl, with many smaller canyons draining into it from all around. The main wash is a flat to rolling desert experience, but the smaller side canyons are very cool, real canyons. Pine Creek canyon has running streams, waterfalls, and thick forest. There are tight cliff walls all around. Most of these canyons have trails into them extending from the loop road. The formal trails sometimes end, but informal rock climber's approach trails continue. If you are careful, you can hike up rock climbers descent trails to the tops of some of the formations, as long as you are VERY careful not to scramble up something you cannot scramble back down. Grab a copy of any of the rock climbers guidebooks, or stop in a shop and scroll through one, to pick up climbs with "walk off" descents. Whiskey Peak, the Rose Tower, the Mescalito, and several other REALLY SPECTACULAR formations can be summited by hikers. For non climbers, this is an opportnuity to get to some spots that usually only climbers get to experience. (Again, the caveats: don't get lost, and don't climb up something you can't climb down.)
TCD