Spraying your non-black boots is best for that even clean finish and then top it off with some clear gloss.
RedaV's Method in its Madness
1: Prepared the boots with a product called Septone - Wax & Grease Remover you can get it from car accessory shop, then wipe them over with Mentholated Spirits
2: Masted up the soul with masking tape, also the pull tabs
3: Sprayed 3 light coats of Silver Leather paint (from shop repair shop)
4: Sprayed 3 light coats of White leather paint (as bove)
5: Remove tape from the sole
6: Sprayed 3 light coats of Extra Gloss over boot & soal (as bove)
Wait till dry then wear! no flaking or cracking
Instant CABoots, good luck
(note:wear your new boots in before spraying)