BetterColorChange

Sorry, I misunderstood the meaning of "background === 'light'" as whether DarkenTTV was off; now I know it means that the color would *look best* on a light background.

I changed the lightening algorithm again, to something closer to what was originally intended; for colors to be lightened, instead of lightening by 20%, I inverted luminosity, darkened by 80%, then inverted again, so even Black, Blue, Red, and Magenta would become light enough without special-case logic.

Below are the results when I ran gulp:
> [07:07:24] Using gulpfile C:\Users\lewisje\Documents\GitHub\BetterTTV\gulpfile.js
> [07:07:24] Starting 'templates'...
> [07:07:24] Finished 'templates' after 473 ms
> [07:07:24] Starting 'scripts'...
> [07:07:24] Finished 'scripts' after 11 ms
> [07:07:24] Starting 'default'...
> [07:07:24] Finished 'default' after 20 µs