automatic backlight control

[DJ Delorie]

Can the keyboard backlight control have an extra step at the end,
going trom "bright" to "dim" to "off/color" to "off/mono" ?

Then the auto-backlight would be allowed to bring it down to
off/color, and the user could go the extra step to off/mono.
(assuming, based on my scant knowledge of the technology, that
backlight+mono doesn't make sense here).

Alternately, have the system remember when the user manually switches
from off/color to off/mono, and use that as the new auto target
(i.e. remember both the "off" user preference (off/color or off/mono)
as well as the "on" user preference (bright..dim)).

Think of it (perhaps document it) as switching between "indoor" and
"outdoor" modes automatically, with the user able to adjust the
settings on a per-mode basis.  On the older XOs, it could at least
remember the color/mono preference for each state, for consistency.

Might be amusing to see if the sensor is good enough to at least tell
the difference between "indoor lighting" (i.e. a classroom) vs "night
reading" (i.e. nighttime without any lights) and offer a third
remembered setting for that.

As for the undiscoverable control, make it a Sugar science activity.
Give the user the actual sensor readings, sliders to control the
thresholds and hysteresis, etc, and let them play with it.  Teaches
them about the sensor, the circuitry behind it, the concept of
"hysteresis", energy conservation (tie in the battery power meter),
contrast, and "industrial" controls.