Usual practice would be to paint it before sharpening, but the de-dinging process will louse up the paint. (Sharpening needn't disturb the paint, and our resident SB guru, Deejay, paints before sharpening.) I think you will need to apply at least a coat of paint to it after it is straightened. You might try discussing it with the technician who is going to straighten and sharpen it. He won't be putting it on the grinder to straighten it, that is a separate operation, so you can probably arrange to have him straighten it, you pick it up and paint it, then you take it back for sharpening.
To get good information on original colours, you will need to hear from Deejay or Steve (deviosi), they are both deeply into what is original and what is not.
