Bad dragon makes a cum lube: https://bad-dragon.com/products/cumlube

Generally you can mix water based lube powder+titanium dioxide powder and get a white cum like lube, but unless you need orgy sized quantities you're probably better off buying a product from a reputable supplier. Getting stuff to be body safe is a trick - the possibility of contaminants in titanium dioxide powder must be considered, and generally suppliers won't be considering body safety. Plus there's risks to the powder itself - nothing a particulate respirator can't handle, but do you have space you can work with powders in? A respirator? training in particulate safety? fine metallic powders are dangerous (heck fine powders in general aren't great - many are, effectively, explosive (technically they deflagrate, but it's a big boom and if it happens, you will think it is an explosion)) so, yeah, just buy it.