Darken JSON strings in SnappyLight

JSON was very hard to read because it was so light.
I darkened it by a couple shades.

Before: http://cl.ly/image/3X2J0N0M3T1c
After: http://cl.ly/image/3W2N0M2G1j37
Merge pull request #48 from jerel/patch-1

Darken JSON strings in SnappyLight