Current colors are too smooth and not contrast. It's hard to read huge JSONs.
My suggestions:
rgba(0,0,0,.87) - for property names (Google recommends that color for black text on pure white backgrounds)
#0B7500 - for strings.
#1A01CC - for numbers and nulls.
This color scheme is similar to JSON Formatter.
This is how it will look like:

Current colors are too smooth and not contrast. It's hard to read huge JSONs.
My suggestions:
rgba(0,0,0,.87)- for property names (Google recommends that color for black text on pure white backgrounds)#0B7500- for strings.#1A01CC- for numbers and nulls.This color scheme is similar to JSON Formatter.
This is how it will look like: