No problem, I contacted the seller OneNineDesign with a welcome and impeccable efficiency. They replied very quickly and sent me as soon as possible a new case of the right color.
I will need other case in the future, and I repeat that choice just for the reliable and efficient customer service.
Regarding the case (I already had one), it is well built and strong, and I find it really class design level.
His only big problem is that it heats up ... It's incredibly Raspberry Pi temperature, even with heatsinks. It's logical there is almost no ventilation.
I noted about 10 ° C higher with the closed case. I am stable at 51 ° C on one server against 42 ° C before.
But he is top, you can not have it all :).
Again thank you for service to OneNineDesign, pleasant and efficient. The quality of service are so rare highlight the need to know.