Nitrocellulose (Nitro) color lacquer . For the selection of the colors I used old Fender color charts as well as real instruments. The colors should represent the original colors of a new instrument, on vintage instruments you can see them e.g. in places under the electronics cover. For a vintage yellowed Relic varnish, choose Nitro Amber Light or Yellow Tinted as the overcoat, this really comes across very realistically. Caution, blue tones can become quite greenish, so it is better to use brown tint.