I hope it's not too late to comment on this
When I first joined SL, I worked to make Ajay (for A.J. -- my RL initials) as much like me as I could in appearance, although she got my 23-year-old body rather than my "spawned two offspring" variant. I mean, I dress my RL body every day. When I come in to SL it's fun to zip back a few years.
That said, my hair color inworld has matched my hair color in RL pretty consistently... although which world's version led the way has varied I first had brown hair, because my RL hair was brown. Then in SL I went more toward red... and over time in RL I did the same.
Now in RL my hair has gone natural (if you find my inworld profile, my first life picture shows me this past December), so Ajay sports a silver mane to go along with that. I've actually toyed around with trying to create some crow's feet at my eyes also, but I haven't had much luck. I don't mind aging in RL and wouldn't mind showing some in SL, but most of options I've seen for aging avatars inworld tend to go more toward the stage-makeup variant of aging, rather than just some laugh lines
To me, SL is more another place than it is another plane of existence, so I tend to just be myself. In RL I partake of whatever cosmetic enhancements are available and reasonable; in SL I do the same.
Thankfully, in SL I don't have to lift weights