The grass pattern is nice an erratic. A few suggestions though. As for color I would reduce the saturation, opposing colors with high saturation are hard to look at. Also, grass rarely lays flat on the ground, adding shadow will create the illusion of depth. Also, a highlight on the surface makes it look as if light is coming down. Dirt is also rarely uniform (i.e., a solid color), adding speckles to the dirt obfuscates the uniformity.
Color theory is very complex, and making appealing colors is an entirely separate job. I'd recommend looking at some color palettes. This is the website I use: https://lospec.com/palette-list.
