Question about hair color - different

Factual Questions
1

This
http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=149424
reminded me. Different question though.

Isn’t a hair’s color determined right at the root? I mean, barring extensive sunning and/or washing and/or chemical use, a hair that is red at the base should be red at the tip right?

Here’s what I know, based on my memory of the Word of Cecil and my own eperience:

  1. Hairs grow from specialized pores on the skin - hair follicles. They each grow at different rates, and fall out after different amounts of time. Hairs close together (for instance, on a cheek) will have similar growth/fallout patterns. I’m currently ignoring shaving {see below}
  2. My hair is all over the spectrum. When it’s dry and clean, say an hour after showering, the top of my head is a medium blonde. As you go down from the top, the hair gets darker until the stuff in front of my ears is almost black. The hair on the back of my neck is medium brown.
    My mustache is blonde, very blonde. So is my imperial (soul patch for some of you).
    My beard, when I have it (now I’m clean-sahven - the stubble looks black), is a fairly unifrom dark brown WHEN IT"S MORE THAN A QUARTER INCH THICK! The strange thing is, when I trim it tight, say an even eighth, it’s a smorgasborg of color - a cornucopia, a palette, a swirler wheel, a <whack!> Right! Dark red, light read, light blonde, all the browns, weirdness abounds.

The strange thing is that when my beard is longer, it’s brown. Completely - nothing else is visible.

Is this normal? I mean, do hairs share colors after growing together for a while? Are the odd colors falling out sooner?

As for #1 above, does the grow/fall out process continue despite shaving? I mean, say there is a hair I have, any old hair, say one out of the 2,347 growing on the lefct side of my face, and it’s supposed to grow for 3 weeks, stop for a week, fall aout and start again. What if I shave it after 2 weeks? Or daily for that matter? Does the little bulb fall out as it’s scheduled to?

2

It probably has mostly to do with the length and moisture of the hair. Generally speaking, the shorter the hair, the lighter it’s going to appear, and the wetter it is, the darker. Also, the shorter it is, the faster it’s going to dry, hence it will be lighter sooner. This works on basically the same principle as fiber-optics, and it’s the same reason that even though polar bears have black skin, they appear snow-white, because of the way their hair funnels light. In addition, I suspect that short hair could refract light in much the same way that an oil slick might, producing a rainbow effect, hence the “smorgasborg of colors”. Also, since shorter hair doesn’t produce much shadow, subtle color variations are more visible in it - that might also be the cause.

That’s just my guess, though… I’m sure someone out there knows better than I do…