I would really find it helpful to have more choices of colors to choose from. Even one more but I don't know why you couldn't add several. Here are some suggestions. Light grey, light orange, light purple, light brown.

Please!

I agree on the need for more highlighting/marking options. Mantis is my Bible app of choice. It is the one I recommend to others. However, five colors is very limiting. Logos Bible, for example has nine highlight colors, fourteen emphasis markup options, etc. to highlight words. Increase the color options and adding other mark up options would certainly make Mantis more useable, desirable, and competitive.

Purple would be nice. I use iBooks and I would like to at least have the same color options to cross-reference. A simple red underlining would be great too.

Still waiting for this request please. It's coming up one year and I really think it would be a nice improvement.