Colors on the Dial and Their Meanings
On Tarantula's dial at left, some of the numbers have a background color, such as an orange background on the 8 on movement, and a red background on the 9 on attack. These colors actually represent the powers and abilities that the HeroClix figure has. Orange on movement, for example, means the ability called "Leap/Climb"--this means that Tarantula can move over hindering terrain, water, and past opposing characters without stopping. Red on attack means the ability called "Blades"--this means that when Tarantula attacks, she can replace her normal damage of 2 with whatever comes up on a 1d6 roll, giving her the opportunity to deal an opposing figure SIX damage! :)
These colorful powers, known collectively as "powers and abilities," can turn a Clix figure that looks unimpressive in numbers into the key piece in your team. The example I gave in my article on "good" numbers" was of experienced Destiny; she's downright weak in terms of stats, but Probability Control (light blue on her Damage power) makes her playable.
Powers and Abilities References
The most recently updated list of powers can be found on HeroClix.com's Rules Downloads page--look for the most recently dated "Powers and Abilities Card." (Spanish and Italian translations are also available.)