If you want color, I would add it to your concrete,during the pore, it can be purchased from a concrete products store or some concrete suppliers have it. The driver adds it to his mix in the truck. Or acid dye can be added after the pore. Epoxy floors are great for basements and garage or storage areas. You will not be happy in a shop environment, if you drop a tool it will chip, welding a cutting with a tourch will damage it also.
I worked for an auto dealership, the owner did half the shop with water based Rust-Oleum, it came up in sheets within a year. Next it was stripped and done with the best Rust-Oleum, that lasted 3 years with some problem spots. The dealership was sold, and the new owner had pro's come in and shot blasted the floor, after 6 years it held up good, except for weld spatter damage, if water gets under it near a seam or damaged area, it also lifted, but did not peel. Then we moved to a new building, there was no epoxy installed, because of past problems.
Dave