Do you have a set reference.

i want platinum bronze silver gold chrome bras titanium stainles steal did yu know titanium nitride look like gold

If you can post a set reference mentioning the needed colors (do you need colors?) then it can be arranged. Custom colors are currently not added to Mecabricks as they don't exist in real life as well.

(Also note that in the workshop, there's a legacy checkbox. You might find the needed colors in there)