How can I make a grainy/noisy looking material in Blender Cycles? I want to have a node set up where I can create a grainy material of my choice of color, with a noise variable so that I change the level of grain shown.
You can set the color directly.
Or use the texture to control the mix of other colors.
Or different shaders.
Or you can use it to combine with other textures and types of noise, as described in this answer: How do I make a Decal look worn?