Hey Ksalmi
I'm not saying get heavy but there is obviosly a quality issue.
The colour should stay constant for at least the warrenty period. Its about how you explain that there is a
problem that counts, desk thumping will achieve nothing wher'as a very polite but firm stating of the facts should work.
If not go direct to Seat UK who I have found pretty helpful in the past.
I work in 'design for mass production' and getting it right is pretty important otherwise we would all be driving trabants!! Know what I'm saying?