I have been looking for a mod that allows you the customer to change a bit more control from the cart. As well as being able to remove a product from the cart and change quantities, I am looking for a way of being able to change the value of attributes.

eg. if a customer buys a blue, medium tshirt and then realizes they want to change the colour of the tshirt to red (without removing it from the cart and starting again)

Has anyone made anything / come accross anything that allows this?