Why min-colors 88?

[Bill Wohler <wohler@newt.com>]

Can anyone explain the magic number 88 to me? Why is this used throughout Emacs?
Why is this the default generated when customizing a face (on devices
with lots of colors)?

I'd understand 16 (larger than the number of colors in the console and
the number of names defined by W3C HTML 4.0), 216 ("web-safe" or 256-40
colors reserved by the OS), and 256.

An MH-E developer has a device where (device-color-cells) returns 64.
What harm could there be in changing our specifications to use 64
instead of 88?

Finally, why are there a lot of faces with seemingly redundant
specifications such as this?

  (defface highlight
    '((((class color) (min-colors 88) (background light))
       :background "darkseagreen2")
      (((class color) (min-colors 88) (background dark))
       :background "darkolivegreen")
      (((class color) (min-colors 16) (background light))
       :background "darkseagreen2")
      (((class color) (min-colors 16) (background dark))
       :background "darkolivegreen")
      (((class color) (min-colors 8))
       :background "green" :foreground "black")
      (t :inverse-video t))
    "Basic face for highlighting."
    :group 'basic-faces)

Seems that this could be simply represented as:

  (defface highlight
    '((((class color) (min-colors 16) (background light))
       :background "darkseagreen2")
      (((class color) (min-colors 16) (background dark))
       :background "darkolivegreen")
      (((class color) (min-colors 8))
       :background "green" :foreground "black")
      (t :inverse-video t))
    "Basic face for highlighting."
    :group 'basic-faces)

Thanks.

-- 
Bill Wohler <wohler@newt.com>  http://www.newt.com/wohler/  GnuPG ID:610BD9AD
Maintainer of comp.mail.mh FAQ and MH-E. Vote Libertarian!
If you're passed on the right, you're in the wrong lane.