I decided that my current paint storage solution was wholly inadequate; consisting of three multi-tiered spice racks from Bed, Bath & Beyond and one MDF rack I bought off Etsy. After a quick Google search, I found some good ideas for an upgrade.
The two racks combine are five feet in length and two feet tall. They are almost completely full but I have a little bit of room for expansion. When I run out of room I'll probably build another similar one and expand upwards. The amount of desk space these racks freed up is staggering; I wish I had built them sooner! For comparison, here is what my desk used to look like: