new CG-very fickle 2b wave..some days could be a 3a, other days its super straight (like today with humidity its just barely a wave, more volume than anything)

I am a natural med to light brunette with hazel eyes and I have been dying my hair for as long as I can remember, all sorts of colours but most recently past 3-4 yrs a dark ebony-darkest brown before being black colour, permanent dye.

I have always straightened my hair, but now deciding to be kinder to my hair I am questioning touching up my roots before going back to work ( i am on maternity leave until sept 12) I dont want to lose any wave/curl or loosen it, infact I want them more defined and tighter but I dont want to show my greys (im only 30!!) help? anyone? suggestions welcome and appreciated
Thanks!