Has anyone considered that when it comes to any product that uses a colour process that different runs have lot #'s. The best QC in the world cannot gaurantee identical results everytime. When we order brick for large jobs I have to specify if I want all one lot run to ensure the colour consistency for my customer, nothing worse that switchng dye lots half way through a job then try to explain to the customer why it looks different. This would also apply to chip runs, The only way they could ensure the same identical colours would be to run billions in one lot which isn't feasable or sensible. If the mix is off slightly on subsequent runs you are going to end up with a slight variation, ever had you car repainted after an accident? does it match perfectly?