Colour matching - identify the correct colour
Most cars have a paint code number, either on the VIN plate, a sticker under the bonnet or boot, in a doorshut or even stencilled somewhere. Finding this will help identify the colour name. Some old codes have now been reused, so the year of manufacture is needed as well. Once the colour has been identified, a check with your paint supplier should reveal whether only one formulation exists for that code, or if there are multiple shades, called variants. These alternative colours may be a tiny shade different, or in some cases almost a totally different colour. It is not unusual to have ten or more `variants' for the same colour.
Car makers are supplied by many different paint companies, aftermarket refinish paints are produced by even more. Some are well known names, e.g. I.C.I or Dupont, others have names that are generally unknown and unpronounceable. All of these could supply a colour, say Ford Radiant Red, which would match an original Ford panel, but mixed using their own specific pigments and different formulas. This method of producing the same colour by different means can sometimes produce odd results, such as a red or orange panel that appears to match perfectly in daylight, but looks like black against white under artificial or street lighting.