From Sonic Retro
Chroma-Cammo is Espio the Chameleon's ability to turn invisible. Combining his ninja sneakiness with the innate chameleon capacity to alter his colour, Espio can render himself undetectable by both Eggman's robots and other characters.
The move is first named when it appears as Espio's signature move in Sonic Rivals 2. Pressing when the signature meter is full sees Espio go transparent (or completly invisible on other players' screens). In this state Espio can't be hit by any of the various hunter-seeker power-ups that are routinely fired around the track in a Rivals 2 race.
Although Rivals 2 was the first time the move was named, Espio's invisibility appeared as a very useful move in Sonic Heroes too. Switched on and off as a secondary effect of the chameleon's Leaf Swirl move, Chroma-Cammo would allow Espio to sneak through the level undetected; an exceptionally useful skill in the Frog Forest, Egg Fleet stages as well as the extra missions of Ocean Palace and Hang Castle, where not being spotted was a requirement to complete the level. In this state Espio could also walk through laser barriers unharmed, which could save time and effort when attempting an A-rank.
- In Sonic Heroes, Chroma-Cammo versions of other Speed formation characters besides Espio are passed through the secondary effect renderer, but these weren't used as the game was programmed only for Espio to use this effect using Leaf Swirl. Other side effects such as with Amy being invisible causes her hammer to be hidden and they can still be detected by enemies or frogs. On the PC version, the Chroma-Cammo effect renders exclusively for Espio and others including Sonic, Shadow and Amy aren't rendered with this effect when being invisible.