This was a kind of ground rice pudding that you made up with milk in a similar way to custard powder.
It was yellow. I adored it and my mum fed it to me all through the 60's and 70's.
I loved it best REALLY thick so she used to make it double the quantity of powder to milk than it said in the instructions, and you could nearly cut it with a knife.
Because I never liked Christmas Pudding, my Christmas dinner always ended with super-thick rice creamola, and I was in heaven. I haven't seen it for years. If I ever do I will mix myself a triple-thick bowlfull and sink into paradise!