Black upvc pario doors

[Alexalee]

I have been getting quotes for the back of the house new sliding patio doors all 2.4m x 2.1m. The current wood ones have warped very badly so that is not an option.
Upvc prices are around 5k for all 4 fitted.
Aluminium are more like 10k
I have heard some storys about black upvc warping and being difficult to open/close/operate after a hot day. My garden is south facing ao in the summer gets about 12h of sun directly on the doors.
Has anyone had a problem with this?
Thanks

I have white UpvC facing due south - and they can be very hard to open when the sun's been on them! They're not new; we inherited them from previous owner.

Thanks. Thats my worry... if white expands that much then black will be a nightmare