Peter is the most unchanged of the actors. Poor Colin. Somehow, I thought Colin was taller than Peter--man was I ever wrong.
Of the first seven doctor, I think Sylvester has aged well too. Troughton looked pretty much the same in the 80s as he did in the 60s, Pertwee looked almost identical in the 90s a to what he did in the 70s, time with Tom hasn't been very generous, Davison has aged okay, Colin is unrecognisable, Sylvester hasn't aged since 1996, and time has been extremely generous to Paul McGann. In some ways, I think his very slight aging actually suits him. And he's 53 ye looks 43! And he's only two years younger than Capaldi but looks ten or even 15 years younger!!!