In order to get a sense of the colour balance and to judge how many more casts are required to fill the shelves, I moved all the casts for the shelves into the shelves. Some do not fit perfectly, so will need to be sanded, but it gave me a good idea of how many are still required and what colours I need to make more casts.
The majority of the new casts were either uni-colour or a limited number of colours so as to balance the shelves as they are currently very 'busy'.
I then re-filled all the moulds with pla ster to make more casts of both floor tiles and casts for the shelves. Again, I focused on using a minimal number of layers to create simpler forms.