It would be easier to get a key that is in the style you want and then cut that one down. An aluminum key, brass, etc. A painted one.If you paint it, it will eventually wear down and the paint will chip. If you coat it, you might go outside of the tolerances of the lock (depending on it's sensitivity, unlikely however).They sell 'titanium' keys that are made of aluminum and come in different colors. This color won't fade.Silva makes Ultralite keys that are done in a titanium alloy.Looks like it might be difficult to find a colored key in that style. The easiest option is going brass.Sent from my Pixel 3a using Tapatalk