Ok so I got as far as getting the colors I want, and making them gradient. Now my question is how do I get the colors to wrap around a circle mesh like the rings around a planet? Im guessing it has something to do with mapping?
In Cycles
A rings texture can be generated using color ramps and object coordinates.
This texture was generated using this node setup.
The key idea is to use one coordinate axis and a color ramp to cycle through the different bands.
For rings about the planet, you can convert the object x-y coordinate into a radius using sqrt(x^2+y^2) and a color ramp.
The geometry is a sphere and filled in circle for the rings.
The node setup for the texture converts the x-y coordinates into a radius, then uses the radius to lookup the color. Also, alpha can be set in the color ramp to make the rings transparent in spots and near the planet.
Adding a transparent color to the color ramp, puts gaps in the rings.