If set, the engine will draw an electric bolt along the projectile path. The colors of the bolt are derived from palette.pal: position #10 (0x0A, slightly desaturated, darker blue) and position #15 (0x0F, white). The bolt can be drawn in an alternate color scheme if .In the first case, the bolt by Yuri's Revenge default is a Blue/White line of interwoven lightning. In the second case, the bolt is by default a Yellow/White line. The second case is typically used for an overcharged Tesla Coil, where the Tesla Coil is charged by at least 2 Tesla Troopers.