Use our own pastel color generator, instead of the randomColor library

I implemented a pastel color library that spits out a random color from
the HSV space where H = [0,1], S = 0.25, V = 1.

This guarantees that the colors are more "pastel" than the ones from the
randomColor library.
increase contrast of background patterns
remove randomcolor generator module in favor of css

Turns out we can generate pastel colors easily using hsl which css
supports. We use H = [0,360], S = 100%, V = 87.5% to generate the pastel
colors.
add example application for gh-pages. no auth required