CSS color(s) replaced with sample from base.png pixel?

I suggest color.module should provide a way to grab a pixel color from base.png from the stylesheet. perhaps something like:

div {
  border-bottom:1px solid #f00; /* color.module: pixel(10,225) */
}

Where #f00 would be replaced by the web color from the base.png pixel at x=10 y=225.

Motivation:

I believe I read somewhere that the algorithm used in image color blending is different (more accurate) than the one used in the css stylesheet, so when you need a CSS color to match an image color there is no way to do so.

Temporary Workaround:

Currently, I've had to use the color.module to produce 1x1 pixel images and use those as tiling backgrounds where I can get away with it. This doesn't work very well when you need it for a border color, though.