@Amy This sounds like a fun ideas to occupy your little one. Can you post pic of such plus to give better idea?
I tend to just Google it, but this is a good website for ideas https://www.earlyyearsresources.co.uk/blog/10-coloured-rice-sensory-play-ideas/#:~:text=Ideas%20for%20Small%20World%20Play&text=Get%20children%20to%20try%20and,together%20to%20create%20new%20ones.&text=To%20create%20a%20base%20for%20ocean%2Dthemed%20rice%20sensory%20bins,blue%20and%20green%20rice%20together.
We've got dyed dry rice they both my boys love playing with. Filling and pouring, making shakers, hiding little toys for the other to find, making different scenes (or using green to make a dinosaur forest, or yellow and blue for a beach) for imaginative play (more for my older one), mixing different colour rice together. It will get everywhere but easily hoovered / brushed up.