In the file engine_equip.ini switch the lines from the other engines until you get the effect your looking for or you can edit the light_equip.ini and change the colors
light_equip.ini
nickname = engine_glow_red
color = 250, 150, 150 - this line is the color so if you wanted to make it a dark red it would look like this 200, 0, 0 or blue would look like this 0, 0, 255
in this example we have the large red and by removing the (play) from playtrail
it add a trail behind the engine exhaust
engine_equip.ini
flame_effect = gf_co_smallengine02_fire
trail_effect = gf_co_smallengine02_trail
trail_effect_player = gf_co_smallengine02_trail
If I am confusing you let me know and we can go into it more