This looks more like some kind of rave than a military engineering facility, but you’re actually looking at a rather colorful stage of aircraft inspection.
In the image, Staff Sergeant Joel Kelehar is washing a component from a KC-135 Stratotanker in what’s known as a hydrophilic remover. So, why all the color? Well, Kelehar is involved in the inspection of airplane components, a process which sometimes uses what are known as penetrants—fluorescent liquids used to penetrate cracks, pores, and other surface defects—to spot flaws. The bath he’s dunking the component in is actually used to remove the liquid, as a simple rinse of water isn’t enough to shift it.
Image by US Air Force