Ribbons have a terrible tendency to fade & discolor which makes things even harder. Blue ribbons faded to white and green ribbons faded to yellow are the biggest pain for me. Actually original crisp white ribbons that are not just faded colored ribbons are the absolute worst, in my opinion. About 2 years ago I bought a giant lot of ribbons and shortly before that I bought a large number of ribbons from another member... so in all I probably had over 500 ribbons to sort through. I separated them by colors then started painstakingly researching each pony to get the best match. I have matched most of my US collection to the best I can, but there were a few where I had to go with "close enough" because sometimes it's hard to tell the exact color shade when looking at pictures on the computer screen. I'm actually afraid to get rid of my left over ribbons in case I find any ponies that I could have matched better, lol!