Switzerland Scott #862 Colour Changeling?

I read scb's recent thread on US #1445 with interest including the comments on his find. I have always thought this stamp was a colour changeling induced by chemical change or bleach or whatever.

There is a definite appearance of the yellow missing, greens are blue, etc. but I could never explain why, other than bleach, the red inscription at the foot of the stamp was so washed out. Postmark does not seem to be affected.

Any thoughts.

Colour changeling I'd vote for,
when all colours are dull and differ,
you generally know some wonky business is at hand.

Light damage is a difficult one these days, because most dealers
do not have their stamps in windows, and the cheap Embassy brand
do not sell in supermarkets any more.
Most probably chemical, how often would a novice soak
stamps in <really> hot water? maybe add a spot of bleach?

I'd guess, that most errors freaks and oddities worth their salt
would always be indemnified by being mint unhinged.
As soon as a stamp has been soaked the possibilities
of poor husbandry takes a quantum leap.

My suggestion is to keep a record of the wonkies you come across
they mount up, and the idea you have a "wonder" diminishes.

There is a stamp in the Aust catalogue that can be easily
made "colour missing" with chemicals.
Despite constant warnings the suckers roll in on ebay
paying weird prices for what they conceive an error.

backroads... Most household bleaches contain components that fluoresce heavily, and thus bleeched stamps are easy to note when placed under UV/blacklight. So I'd check this initially.

Additionally, on my display the paper looks a bit creamy. If so, then I'd say this was exposed to sunlight.

Always be wary of stamps where the green has changed to blue or turquioise.

I have this oddball precancel with almost no ink on the underlying design, but full ink on the precancel itself. The "embossing" caused by printing an engraved stamp is present here, but almost none of the design itself. But under UV light (especially shortwave light), a fairly strong ghost of the image is seen. I wonder what kind of chemical can remove so much of the stamp image's ink without removing much of the precancel ink. Interesting.

Ryan