Planet ring

Hello. I would like to know what’s the easiest way to implement a Saturn ring using the textures found here:
http://planetpixelemporium.com/saturn.html

Any suggestion? Thank you.

You can draw a lot of circles for to simulate the rings with each circle with a different color.

The color of each circle can be selected by a different 1D texture coordinate on the Björn Jónsson’s colormap found at http://planetpixelemporium.com/saturn.html)

If I could pick the color from one texture, and the transparency from the other, that would be great. Because then I would be able to write every circle in a loop.
Is it possible to do that?

You have only one RGBA 1D texture to use.

The RGB part is the color and the A part the transparency.