genuinely if you add me on discord i will absolutely walk you through it ! i can answer here briefly but i can provide visual examples on there !! x.vk

With darker colour palettes I follow the same technique as with a lighter palette (using hue shifting), but up the saturation so you can make out the colors without it looking muddy / grey. I typically make it in a normal saturated style before using a tone curve to make the colors darker / add an overlay on top. I wouldn't say it's necessary to use saturated colors but I personally prefer it! You can always balance the values a little by using brighter colors in places (such as a brighter false light source) or like the pupils to suggest a glow :) Even with a dark tint it's good to maintain differing values even if it's not as dramatic + can help something look more appealing. If it helps, you can make a skin + to check if the colors work together, brighten the image on your phone/program to see if they blend when not under a dark tint :3. (again can provide visual examples for all)

For white hair I shade it with literally any other color lol ,, if you shade towards a specific color (e.g. the darker parts of the pony appear more blue), carry on with that. I typically don't choose pure white and instead a slightly tinted color (e.g. slightly yellow, and shade it like desaturated blonde hair ..) (desaturated yellow - orange - red - pink - purple - blue) but you can do whatever suits the skin the most. Essentially just shade it normally but move the slider around to different colors :3

IDK like.. if you're using completely different colour codes in different patterns it's obviously not going to look exact, but it's still a cheap way to do things i think + you shouldn't really rely on other's work to base your own off of + some people can tell if you just put a tint over their colouring if it's in the same placement 😭 esp if their colouring is quite abstract/unique to that pony

i would avoid doing it but?? i don't think it'd be.. exactly copying it?? it depends how much you're tinting it + changing it. like at the end of the day ur still being lazy so idk i can't recommend LOL.. if u can go through the effort of tinting something i would just come up with ur own arrangement atp ^^;..

it wouldn't be a colourpick but if it's the same character + you didn't change placements i'd probably say it's copieed.d.?? i mean by definition it is you literally just tinted them idk 😭😭 if it feels wrong 2 do i wouldn't do it + if you're only tinting them to get away w copying them thats kind of weirdd... idk 😭 u could always just ask 2 take inspo from their colouring lol