RAL colors for window frames

It is not only the color that causes the surcharge. Darker frames heat up more, the material stress is greater. Therefore, at reputable window manufacturers, more reinforcing material must be installed in window frames that are to become darker, it is probably metal. That's how a roller shutter installer explained it to me.

Best regards Gabriele

muss deshalb in Fensterrahmen die dunkel werden sollen mehr versteifendes Masterial eingebaut werden,

That would mean using a different profile version if it is to be dark laminated - and I don't think that is the case.