Odd spark plug colour

[tihol tiholov]

<snip>
>Would still be interesting to find out why they turned orange, though.

What's wrong with orange?  Most other colors are less desirable,
AFAIRemember.  Like, burgundy (lately aka cabernet) would be
objectionable, so would taupe, never mind ecrue or not to even mention
mauve ;o)))  
I'd enjoy ceramic (terracota, if you pefer) color on my sparkplugs -
nice an earthy.  But my car's 2 years older and only 10V.

(humbly) TT