The Color Gun is a device that Chase McCain can use while wearing his Robber disguise. The color gun allows him to change the color of LEGO bricks. This can have varying effects. Coloring an item silver, for example, allows it to reflect laser beams. The color gun can also be used to activate or deactivate lighted electrical devices by changing their color.
The color gun must be loaded with the correct color. This can be done by finding a Color Swapper.
In LEGO City Undercover the color gun is not initially available when McCain gains the robber disguise, but becomes available during Special Assignment - Dirty Work. In LEGO City Undercover it is possible to avoid the need for color swappers by finding and unlocking Red Brick 37 - Super Color Gun.