A while ago I decided for morning ring I needed my own colour cards so I could test the children and see if they know their colours. They work very well for me so I am sharing them with you. I have the coloured in PDF and the non coloured in one.
Click for coloured in colours
Click for non coloured in colours
The tradition with flashcards here is to put the word a picture on one side and the word on the other side. You can then check recognition of both the actual thing and the word.
Another idea is to have a set of cards with the words on them and another set with the pictures on them. They can then play a matching game.