Just asking if everything is normal because i have some colouring and some and most started a little amber one of the pictures you can see that they change

The reddish/purple is probably normal... if temps drop to 18C and below, it could be exaggerating the Autumn colors, but could also just be genetics. Stay above 18c as best you can at night. The paling of the canopy is the plant cannibalizing the leaves. This is fine as long as the canopy doesn't not deteriorate too fast before you get to harvest. Don't be afraid to feed a plant if the progression of the deficiencies is too fast. Don't be afraid to feed anytime you aren't over-fertilizing for that matter. It's a myth that you need to 'flush a plant' at harvest. Don't starve it. Seems a bit early to check trichomes... you can find amber trichomes at various points - especially on preflowers that are older than the rest of the growth. If the colas aren't fully plumped up, no need to check trichomes, yet. Humidifiers are fairly cheap, so adding one would help the RH situation