Hair Color Camps

It seems to me that there are two types of women: those who are adventurous when it comes to coloring their hair, and those who aren't.
My sister and I fall into the second category. After a run-in during high school with a box of carrot-top red hair color, I've been very hesitant to recreate the trauma. Plus, I have medium-toned olive skin and dark eyes, so brown hair just seems to be a natural for me. So these days, it's all about maintenance. My stylist conceals my premature grey hair with a similar deep brown, a shade or two lighter than my natural color. It's the color my hair would be if I spent time in the sun.
My sister takes hair color phobia to an extreme. She is in her early thirties and has never colored her hair, and she prides herself on her virgin locks. They have never been chemically altered in any way. But tonight, when my mother suggested highlights, she didn't balk for a change. She actually said she had been thinking about it. Which got me thinking about it...
Can two color-shy sisters step up and make some serious changes? We'll see...