We use a lot of Koyo 2RS bearings on Quads we repair, and nearly all have blue shields but are not stainless. The stainless bearings I have bought have 2RS SS as part of the number.
Seals have no meaning as to material of the bearing as far as I am aware, I have seen red, blue, green, brown, black and probably a few more colours on standard bearings.
At the moment stainless seem to be blue seals for the most part but I regularly get stainless bearings for the rollers on fishing boats and black seals are sometimes used.
OK, after a bit more searching, the above looks like this SKF bearing (not stainless) which has a 2RZ which seems to be a non contact seal for high speed use.
Nothing at all, I will use that one, I was just trying to find out the source of the blue one one listed on the SLS web site. I think they have chosen the SKF brand to be sure of "quality"
The lowest cost "brand name" one I can find is this one.