While it's rare for a person not to  have split ends for a longer period of time,it is highly recommended that you do a Search and Destroy mission once a week to get rid of any split ends that you may not see until closer inspection.  This will prevent any splits traveling up the hair shaft.  If at all possible,get regular trims to keep hair healthy.   
I'm sure other members will chime in,(at least I hope they will) with their suggestions and advice,
Please also read about growing healthy long hair,recipes and different natural recipes for coloring,covering grey and highlighting.  Dying is one of the worst things you can do to your hair,there are many other alternatives wihether done at a salon or even right at home!  Take a peek , try and enjoy!
HTH

I don't know what the real state of my hair was when I lived in CA, but I only used temporary dyes that never had the chance to fade.  I shudder at the thought of what I was hiding.  I was trying to mask the sun damage effect I'm prone too even today with UV filters in hair products.   The dark dyes especially are linked to higher risks of cancer which is enough to put me off getting my hair permanently dyed again because I don't suit the lighter shades.  Someone who knows a little more about PPD, what it is, why it's more of a risk with the darker colors, are better qualified to explain this than I am.