On 2017-04-27, dennis home wrote:

On 27/04/2017 12:15, Adam Funk wrote:
On 2017-04-26, Dave Plowman (News) wrote:

Colour temperature to the eye is subjective. The real problem with many of
this sort of light source is they ain't continuous or smooth over the
visible light spectrum. Which can make colours - like paint - appear a
different colour (or shade) than in daylight, or halogen.

This may not matter much in a domestic living setting, but certainly can
in a workshop, etc. Or even a kitchen.

I saw an interesting science demonstration once where the presenter
had a box painted white on the inside, with three lights of different
colours (RBG, I think) shining into it. He turned down the house
lights & adjusted the brightness of each one until the audience
generally agreed that the inside of the box looked white. Then he put
various fruits & vegetables in the box & they did not look right.


Thats because the eye doesn't see a continuous range of colour.
It only sees the relative levels of colours in three fairly wide bands
and the brain constructs the colours from that information.

Its quite easy to fool the brain about the actual colour and what you
think you see.
There are images where you can move a square of material from one spot
to another and its perceived colour changes.
Add in that the sun is not a black body emitter of light and has some
very strong yellow lines in it and you can see why colour varies so much
from person to person.

AIUI, photographs & RGB displays meant for humans won't fool insects
because they pick up 5 (or is it 6?) colour bands.