Micarta is fibre glass resin impregnated with paper or linen canvas.
Just punch it in the internet for a description. Blocks for handle material can be found on Ebay and other knife supply shops.
I have seen it in Green, brown, jade, ivory, red, blue, and yellow.
I'm sure G-10 is available as well. I have only seen it in black.
Cheers,
Hal