Rainbow in the Clouds

It was a cloudy hot day sitting outside at the commencement address.  You can see in the dark clouds on the sides that the sky was just beginning to open up.  I had my camera out already so I was able to capture the moment.

I didn't do much editing, except to crop and lighten up a bit to show the rainbow a bit more.  I still think it could be enhanced more in post-processing, but I didn't want to overdo the color.  Any suggestions?  As always - feedback@inkdropphoto.com.