This idea came after we played some Bean Bag Games - once I had four containers of different colours, it was just a matter of finding some matching contents.
I pulled together an assortment of items for the bins: block, ball, spoon, sponge, pipe cleaner, harmonica - anything that was almost entirely one colour.
First of all I showed them to F with the items in the correct colour bin. Then I made a pile out of all them in the middle, and let him put them in the correct bin. But rather than sorting he was more interested in contemplating each item. When I asked him questions like "where does this blue spoon go?", he would turn to look at the cutlery drawer. Or he'd find one of his building bricks, and want to return it to the brick box. Full marks for tidyness but I have a feeling that at 22m he just wasn't ready for the game.
We kept these around for about a week, with the contents changing in and out daily. We had some older friends come to play (ages 3-4) and we challenged them to find as many items of each colour as possible from around the room. That was a really fun activity for them.
Although F didn't play my intended game, I am sure that by grouping the items together it has made him more aware of the colours. We'll just try it again in a few months!