Usually hold 2-8 or more of Try-All rims in each option, depending on popularity. 28h front rims are relatively rare so fewer of those than, say, 32h 26" rear rims in black. Luckily (for us!) most of the Adamant/Czar/GU/ZOO parts have been discontinued, with just the lever blades, bashrings, cranks, headsets, bars and boosters coming in 2 instead of 6 colours now. But yeah, when they were first released it meant a lot of different items! Those sorts of stock combinations are not something a 'normal' shop would not be confident in having, with mail order you have a much larger 'audience'. Old unpopular colours are discounted if they don't sell within a reasonable period of time usually