Many products offer not only a selection of standard finishes at a standard price, but offer more options at additional cost. Some will offer those options in price groups, such as Standard, Group 1, and Group 2, where each group is more expensive than the last. Finally, some manufacturers offer to match any color.
Unfortunately, the requirements for getting a custom color often are vague, and a minimum quantity may be required or other limitations may apply.
The result? I may tell a project architect that a custom color will cost more, but because I often don’t know how much, the response usually is, “It doesn’t matter; we want custom.”