Would it cost so much to add colors to it ? Sure the blind kid won't see them, but if someone else (sibling, friend etc...) wants to play with it they can too...
This feels like a good idea that wasn't though through entirely.
Usually (i.e. the cheaper way) is to add the braille via PermaBraille sheets (available through APH - American Printing House for the Blind [and other locations but with the federal quota funds available for legally blind students in the US teachers order a lot of these for labeling items because they're 'free to them' via allocations]) with the braille for colors, or more often textures (feel n peel carousel of textures) to differentiate. The rubix cube pictured may be a prototype, photoshopped, or pre-color, but usually the items will have visual differentiation to make them more inclusive. (Even the flip-over concept books by APH have colors as well as textures/parts of a whole/line paths) (If you're wondering why things are so relatively pricey at APH it's because it has to be durable enough to stand up to pretty intense handling and wear. Allocation has been slowly reducing over the years, it's under $300 per registered legally blind student/year these days, APH are good people.)
This feels like a good idea that wasn't though through entirely.