A surface will absorb all colors.
A green surface will absorb all colors and reflect

A Black surface will absorb all colors.

A green surface will absorb all colors and reflect green.

=> Any surface which absorbs all the colors appear to be black because no color is reflected.

=> A surface color is a color which is reflected by it.

For example:

If a surface is red colored, This means that it reflects red color. That's why it appears to be red.

Hope this helped!

what bodys are there orbiting?