Well, in fact, those are regular 37 ABS rainbow color caps I believes. Just because ABS are easier to let the light out.
I possible can get then for like 10 dollars or so.
I ordered two set and try to put it on the LED keyboard to have some picture see if it is the same as what they show.
And, Picture won't always tell you the true, you can't tell how light it is even it light up.