Are these sc upc or sc apc type keystones? being blue i expect they are upc as apc are traditionally green, but wanted to verify.

Fibers terminated with UPC connections are always blue, and fibers terminated with APC connections are always green. When mating two fibers in a keystone bulkhead adapter, blue should be plugged into blue and green should be plugged into green. Connecting UPC to APC will leave an air gap between the connections, which will attenuate the optical signal and may damage the fiberglass. Even though the green and blue connectors are identical, it is good practice to use the green with SC/APC and blue with SC/UPC, as this helps to ensure that both fibers are the same color (style).

Hi there, i'm looking for just the blank insert in packs of 50. just the white part that's shown in the picture. Do you sell these like this?

If you are asking for the blank keystone jack plug, we have those available in packs of 10; http://www.amazon.com/Blank-Plug-Networx-Wall-Plate/dp/B0054RS3LM/ that would be a solid white plug to fill in the blank port.

I'm using ubiquiti simplex lc to lc single mode fiber. can i use these in my keystone rack?

Should be fine. If you're not pressed for time, order a few to test...then get more if they prove satisfactory. This way you can also check their fit into your keystone panels.