CAPT...
Cool, glad that worked for ya. That'll help me annotate that in the next README, so that others can get the full effect without it chopping up.
Yeah, the way to change the color on the end is to change the R G B "color end = xxx, xxx, xxx, xxx" values (0-255) under the "// propulsion wake //" header to whatever you want. Personally, for a fading "less dark" effect, I'd start with some faded whites (210, 210, 210) and work to white/grey (195, 195, 195) and then down to greys (125, 125, 125). And just to re-iterate, the last value is the alpha, so for all the COLOR END values it should be 0 (ie. color end = 125, 125, 125, 0) for fading out.
If you get a ending color fade you like, throw that same COLOR END entry onto the "// keel wake //" section as well and see if that makes it even better.
Later
Sludge