As with any game with distinct sides to choose from - chess does not have the following problem but StarCraft does - Magic sometimes suffers from hard choices in terms of faction (or in Magic's specific case, color) balance. It can be easy through negligence, underestimation, or favoritism to make one faction or color too strong or give it too much of a variety of things to do, or to make it too weak or to give it too few effects. Of course, a game like StarCraft can release patches to change the functions of units and its designers know that any given Terran, Protoss, or Zerg player will have access to the same unit pool. Magic does not have the luxury of functional errata and the card pool each color has in each format changes with each set release. The one benefit of this is that the pendulum can be allowed to swing back and forth for each color, but there are also things ingrained in the color pie that will always be there. And despite recent efforts, it seems red has the fewest.
Red's purview consists largely of things that are purely destructive in nature, and it suffered, for a while, from a lack of "positive" (adding to your own resources rather than blowing an opponents' up) card advantage, save for recurring or tutoring sorceries once in a while. The latter issue has more or less been fixed with the recent additions of looting and use-it-or-lose-it card "draw," but red could still use more proactive things to do. Here are some suggestions.
Make spell copying exclusive. Blue and red both get instant and sorcery retargeting and copying, which seems to muddle things. Blue, as the color of countering and hexproof and mind tricks, can more naturally or natively get target changing. Red, the color of emotions run hot and excess, should be more adept at putting extra oomph into spells.
Temporary and fragile life boosts. Blue, the color of false images, got, of all things, the Illusions of Grandeur effect once upon a time. Red at least has slightly more business getting that effect, being much more concerned with the physical body and having the precedent (no matter how strange) of Soulgorger Orgg. Besides, a red with ridiculous forms of defense is a red I can get behind.
Switch power and toughness with other things. Switching power and toughness with each other is classic red. Tree of Redemption shows how far this tech can go. Switching power with hand size (hint: Discard the hand, draw cards equal to the appropriate creature's power, then set the power equal to the number of discarded cards) sounds silly and strong and fun and above all red.