It's a suggested enhancement. With swipe-to-star it would be really awesome.
I don't use star flags at all (I have hidden the icon in fact) or set any read/unread backgrounds (I use bold coloured text on the subject line to indicate unread messages) so that wouldn't be of much use to me, but I can see it being very helpful to others.
My own issue is that I have four email accounts, and the most obvious way to highlight which account any given message is from in the Smart Folder would be to add a light colour wash to the background. I currently use the corner flash option, but it's too small to be very noticeable (especially next to a colourful avatar image). The current "Account name" option takes up an extra line for each message, which is not ideal either.
Andre
