Filipinac's 2018 Sprites

Ok then...Hold my beer.





Notice how it is not locke front and back, nor is it even perfect imo i simply made it to give you an idea of what you can do
Uses DEFAULT pallet #4 and none of the last four colours.
also i noticed you didn't bother with the different arm poses on the second line
these are needed as its how the characters use weapons and appear in menus etc
next time try to not just use locke as the front and back (in fact for front and back poses that aren't being directly copied from rk delete them,
look at how the other sprites move details down as they go from side view to front and back(that is how i made this)
i looked at how sabins face moved down from the side view by two pixels for the front facing view as a reference and drew the front and back to the rk sprite in a similar way
and yes it took a good few hours. its not a race at the end of the day. i'm sure u'd rather post one really good sprite a month then 10 like this.
Everything LordSutebenu said u should take on board. ff rk is a great game i agree but it does not have front facing sprites or back, so u need to learn how they are constructed in ffvi,
also the base for this was shadow. i bet u couldn't tell. that's how it should be really
i hope this helps explain somewhat. if you need any help in future shoot me a pm and i can give u some tips.
keep trying. everything takes practise

This is actually a pretty good sprite sheet though.
The hair can be cleaned up a little bit, but the outfit is pretty on point. I enjoy the cinching in the back, that's a great eye for detail. 
As it is, I would say for the OP to maybe borrow this and make a Noctis sheet that is his own. I think the palette in this is a good one, and has the foundation to be amazing.

as far as colors, in this sheet, I would use the bluish color that you put on the vest as Noctis' undershirt. The way you have the vest sprited actually allows for a nice transition with the blacks. 

Also, I'm living for that Carbuncle. I love it.