I'd never color my hair myself. Stylists go to school to learn this stuff and I wouldn't mess with it. Just my opinion, though. Fortunately, what I have done is a simple single process color with no bleach. I had highlights for years, starting in my early thirties, when my blonde hair started getting darker. But, as I cut my hair shorter, they never lasted more than one haircut, which for me is 4 weeks. So, about 2 years ago, I started the color stuff and it's worked out well; it actually looks like highlights growing out and I go about 3-4 months between colorings. Much cheaper, too.
My hair is really dark now, all of the color is gone. My stylist had surgery for carpal tunnel in her wrist, and can no longer cut hair, but still does color. So, I just had my 2nd haircut with a new person and I have an appt. with my original stylist for color in 10 days. For the first time, gray is becoming an issue. I consider myself to be very lucky to have my first good amount of gray at 58, so she will need to make sure that's covered. I constantly go between telling her to make my hair "whiter" or go back to "golden," which was more my natural color. Somehow, the golden shades seem to look red on me, which I hate, and the whiter blondes wash me out. I think if i can find the happy medium between what I had in November and the lighter one I had before that, it will be perfect.