This is a subject that could be debated all day long. But I just happen to have a copy of Leo fender's notes to go off of. Although it has changed many times over the years and sprayed by many different people. The bottom line is. It was always done with either dyes, toners, shaders and of course clear coat. Here is the way to get the 4 most sought after Fender sunbursts.
(54-56) 2 Tone Sunburst
These were in Yellow and Dark salem. On Ash. First the ash was filled using a natural grain filler. Then it was sealed using a sealer and made sure to be a flat surface. The yellow was then sprayed on over the flat sealer usually followed by 1 light coat of clear lacquer (the clear will lock in the colour) Then the Dark Salem Burst was applied. Either normal or a wide burst. If there were any mistakes it was put aside. If it was perfect... or close to it was then clear coated.
Post 1956 Sunburst
These are still yellow and brown. They switched to Alder though. Mr Fender thought it was to dark. So they bleached the Alder tops and backs. To make it look as light as the Ash bodies. The undercoat is a yellow "Stain" or "Dye" that is right on the bare wood and then sealed with either sealer or clear lacquer. A NGR stain will work or our yellow toner.
Pre 1964 Sunburst
This process is identical to that last burst however they added a red to the mix to make it look more appealing and brighter. The red is always sprayed last. Yellow, Dark Salem, then blend the Red in.
Post 1964 Sunburst
You guessed it. On Alder. But... this is when Fender decided they didn't want to bleach the alder anymore. They also decided they didn't like 1-3 piece bodies anymore. This lead to them using a "whiteish Yellow" toner sprayed over up to 4 sealed boards of alder.You'll know these when you see them. They are ridiculously yellow and almost opaque (so you can't see how many pieces of wood make up the guitar.... Thanks CBS. However the look is an important part of fender history.
Just remember, when you put a colour in. Always, always "lock it in" with a coat of clear lacquer. The toner will melt into the guitar like it is supposed to. But lacquer has a tendency to shrink things back. That is why this step is done. They still do it in the custom shop today.
1) Sealed, then yellow sprayed or "Stained" followed by a light coat of clear lacquer.
2)Dark Salem Followed by a light coat of clear lacquer ( after you spray your Dark Salem it is a good idea to tack cloth off any "overspray" from your burst wipe very lightly with the grain before you lock in your Dark Salem colour)
3)Red (optional) Aim more into the Dark Salem edge than the yellow and blend in the red. Followed by light coat of clear lacquer.
4)Top coat 4ish coats of clear lacquer.
You will need, a sealer (sealer or clear coat), your choice of Toners and multiple cans of clear coat for a build.
Any sunburst that didn't meet the mark was put aside... and you guessed it was repurposed... For a custom Colour. Since then these are highly sought after instruments. So many of Fenders "mistakes" turned into gold years later. And you thought the V neck was on purpose.... sometimes people need vacation or call in sick. And that's how the V neck was born. They should call it the new guy on the sander profile. But we're talking about sunbursts here.
Gibson sprays their sunburst colours very similar to Fender. It's all done with toners and shaders. Their early red faded like crazy and created a line of very rare 58-60 bursts that could be worth more than your house. There is also the ever popular tobacco burst, and the newer blueberry burst. You can use our dye stain to colour the top of your maple cap to your liking or use our yellow toner that comes in aerosol. Make sure you tape off any part you don't want colour on. You'll probably end up having to scrape your binding with a razor blade... But that is better than overspray everywhere. Remember once you apply one colour always spray a light coat of clear lacquer over it to lock in the colour and make your work easier.