Why tires are in black colour?

Tyres are mixture of various rubbers with carbon black added. Carbon black improves traction and wear resistance of pure rubber.

Another reason is that black color has higher absorption capability by which the tyre of any vehicle becomes adhesive to road.

Afterburner:

An afterburner (or a reheat) is an additional component present on some jet engines, mostly military supersonic aircraft. Its purpose is to provide an increase in thrust, usually for supersonic flight, takeoff and for combat situations. Afterburning is achieved by injecting additional fuel into the jet pipe downstream of (i.e. after) the turbine. The advantage of afterburning is significantly increased thrust; the disadvantage is its very high fuel consumption and inefficiency, though this is often regarded as acceptable for the short periods during which it is usually used.