My eldest is 2 years and 2 months and loves doing matching games. I printed out this colour matching activity from The Helpful Garden. This blog is amazing and she does really great activities and nomenclature cards etc that you can download and print for free! ( I downloaded her Blue Series reading activities for a child I work with).
This activity has a picture mat for each colour and cards to match. I chose two colours my daughter struggles with (right now, if she doesn’t know the colour, she calls it blue or pink), then got her to match the picture card to the mat. I asked her what the picture was then got her to tell me the colour of the item named. I mixed up two groups of cards and she really enjoyed the activity. It teaches colours as well as vocabulary!