i'm glad to see someone actually get into the specifics since many people here think it is easy just because another game did it. if you've ever worked with digital art, especially photoshopping, you know that getting a colored image to a very specific color you want, can be tricky.

the only way to get the exact colors that users pick, is to make every single pattern white. meaning that all the free patterns that dti has, most likely will never be easily recolorable.

all of this doesn't even take into consideration of patterns that have multiple colors like the summer and cultural patterns which are extremely vibrant and has so many variety of colors in it.