Purple, Burns ?

Aight, so I've got my three babies and one looks fantastic, bright green all over with purple buds!

Then there's lil whitey who looks great but her biggest fan leaves are looking kinda peach and violet colored, which might just be it changing colors and the buds will too soon but I'm not sure this is only my second grow!

Last but not least is my big purp, she doesn't know what color she wants to be, but she's also got dead dry almost like burns at the ends of some of her leaves, along with a lot of the leaves turning purple.

Just wondering about the second two, especially the last because the purple looks great but the burns are definitely not good!

Any questions, comments, advice, answers very welcome thanks
pics below and this sexy pic just cuz it's so sexy

Outdoor? Indoor? Nutes? Soil? More info. needed.

is he growing in soil??

it looks like nitrogen deficiency in pic 3

Obviously outdoor in soil, the soil is just some garden mix it's somewhere I can find it if it's that important.
Probably every 2 or 3 times I've watered I've given them 1/4 a normal dose of miracle-gro houseplant food
I water em every time the soil gets dry about 1 1/2 to 2 inches, we've been getting mostly clear skies, bright hot tucson, arizona sunlight, at about 12/12 of course the days have slowly been getting longer since jan...

And if it helps, I started them out indoor under daylight flouro's until about the 5th node then they went outside and I put them from cups into pots.