so is this anthracite gray (RAL 7016) a standard color and a slightly lighter gray would cost more?
No, that's not correct. Just type "window color palette" into Google and select, for example, the link from "Weru" windows. Their standard colors are listed there.
- White is the cheapest for plastic windows
- Then come the so-called "standard" or "preferred colors" depending on the manufacturer, which cost a bit more than white. These usually include anthracite, brown, lighter gray, etc.
- And only if none of these preferred colors are suitable, can you go for an individual special color according to RAL and choose any desired color. However, this is naturally even more expensive. If necessary, you would then also have to apply this special color to the garage door and the front door, if everything is to have the same color.