From that view, I don't see a vintage Marble King Rainbow, or a modern one.
The vintage Marble King Rainbow looks like so -- it's called a Patch & Ribbon pattern. Ignore the first marble here for a moment. It's a Tri-Color Rainbow. The typical P&R pattern is Patch on top in Color 1. Ribbon of Color 2. Ribbon of Color 1. Patch on bottom of Color 2.
Modern Rainbows do have two patches, one on either end. Usually but not always the same color.
So ... back to your marble. It could possibly still be Marble King with that combo. Or it could be Vitro. OR, and this is how I'm leaning at the moment, it could be an Akro Tri-Color Agate.