Re: 59/C hybrid dark in strat
No two guitars have the same needs. Plus all the different types of mahogany from Middle Eastern Nato (Gibson baldwin starter guitars to BC Rich NJ Deluxe) to Honduran Mahogany. I've never liked a guitar made of Nato.
starting off easy
If you're not a coated string fan start off with trying steel strings. Nickle Plated steel are very versatile and will always have a place for many but if I need a brighter tone try stainless steel or similar strings Fender to Ernie Ball to Dunlop Super bright strings will do the trick. Whatever brand you have most likely they them. Even standard Ernie Ball strings start off too bright for my taste but ok what else can you do.
next I'd adjust the pole pieces if you haven't this is the video in my book marks I show people
https://www.youtube.com/watch?v=jXIggQxlAhc
a fender no load tone control (or two) - I got the inspiration from Yngwie Malmsteen signature model guitars. His pickups would be too dark and warm with a standard fender strat wiring so this is how he combats it. At 10 the tone capacitor is not present in the guitar and this increases the volume (subtle) and resonant peak of the pickup(s). Turn it below 10 you feel a stiffness similar to a blend pot and then your tone capacitor is back into the circuit so you could even use a really high value like 0.1uf (100nf) and as they say get your cake and eat it too as the 100nf would cut a much higher amount of frequencies as you turn it down to 0%.
Perhaps try smaller tone capacitors - Depending on the gap in values can be subtle or extreme. Extreme being from 100nf to 22nf. I'd suggest 0.022uf (22nf) to 0.01uf (10nf) -
if your wiring permits it use 1 capacitor instead of 2 as well. Any type of capacitor material besides ceramic (flat orange discs) or MLCC capacitors which are also ceramic. Green/red polyester is fine. If you're going down in values from a standard 0.047uf (47nf) to 0.022uf (22nf) you'll hear a difference even if you made the capacitor out in a tool shed as we're heightening the resonant peak of the guitar. The down side is if you use the tone and roll to 0 a lot you won't cut as many frequencies so this is why I mentioned the no load pot first.
If you've got a lot of time to spare this weekend. Check to see how closely the pots are to 500k. The higher the pots values are the brighter the guitar becomes. When I used to do project guitars if a pot I tested prior to putting in a guitar I wanted a brighter tone was below 470k tested I wouldn't use it.
If it was me perhaps I'd suggest getting rid of the 250k pots in the guitar
