just checked over and wanted to say that there's nothing wrong with the nutrient ratio you're growing at(3-1-2) but a lot of growers like to up their pk as flower progresses. some people may tell you your nutrients will be bad in flower, etc. but there's a lot of scientific support to using that ratio for cannabis and tons of people killing it with that. that said some people will tell you it's all wrong and horrible. do your own research and decide. the owner of
dynagro is a scientific based supporter of the foliage ratio(the ratio you're using) for cannabis and has tons of good information on it from studies he's funded. your nutrients sound complete and fine though.
do you have a ph and ppm meter yet? those are the next step and will allow you to understand what you're feeding and why.
as the hairs age they dry, recede, and turn orange or red commonly but can be pink, purple, or red and probably others. a plant is ripe usually in some phase of the hairs being almost completely orange to completely orange for some time. the real way to check is to use a magnifier and view the crystals. without one, you can still tell when they're mostly cloudy if you know what to look for. the crystals start shiny and long and reflect back like glass or sugar. as they fill they get shorter and thicker. more straight and cloudy. they'll look more like salt then glass and fill with light but not reflect back like a diamond. when almost all the crystals look like this and the hairs are almost totally orange or totally orange, chop it. should take 60-75 days most likely from the day you started 12/12. if you start seeing a lot of amber crystals reflect back, she's going over ripe. after cloudy the crystals turn amber and switch thc rapidly to a different, less potent, substance.
be proud, great first grow just finish her out.