Ok, so my current project has spent some time sitting.  So I spent some time color sanding and then buffing.  It shines up, and is smooth, the chalking is gone, but the white on the bow is still a bit dingy in places, similar to the dark on a hull when it's been in the water a couple days.  Not that it doesn't shine, but it looks dirty.  Cant seem to buff or color sand that out.  Hit it with some 400 grit, which helped, I don't want to sand too far though.  Any tips/tricks or readily available product that might help?  If it was a sink I'd use bleach, don't think that is good for the gel though.  Thanks