As Raymo said, if you shoot some short subs that capture the Trapezium you can then layer them in processing (which you would have to be able to do of course). This will prevent the over-exposure in the central core.
As to the color, I agree it needs more, but that could be due to my shooting the same object with a full-spectrum camera and being used to seeing it that way. Certainly your closer to monotone image is perhaps closer to a visual experience. One of the advantages of imaging is the colour potential it provides.
Great start, and you must be prepared to stay up waiting for it to rise at this time of year.
