[gwrightson]

Ok fellow c/c.s 
What are your opinions of this? any idea of the cause? 

Brownie point for 1st correct answer

[Peter Sweeney]

Too many variables but I can fix it

[Adam P]

skylight? that part of the door to the right is always closed to people walk to the left and the traffic has caused this? aliens?

[JandS]

You cleaned the blue bit.

[Dennis]

Walkway from some kind of chemical factory where people aren't supposed to walk from the manufacturing area but do anyway and it's changed the colour? Although it seems too uniform for that. 
Really strong prespray on the dirty bits and just a rinse on the clean bits so needs a ph rebalance?

[gwrightson]

Too many variables but I can fix it

The only way you fix this peter is to replace,

got to admit when I first saw it I was thinking  what the hell has happened here, same thing going up open plan stairs in an office building.

Believe it or not it is actually the colour of the tiles , the design apparently was to have blue merging into grey .

Geoff

[elliott cleaning]

That's purely colour loss. Get the client to shut the left hand side door & get the staff to walk on the right. In due course they might be lucky to end up with a slightly more uniform corridor

[gwrightson]

No Elliot,

they are 2 different coloured tiles , its how they wanted it

Geoff

[Dennis]

Some people will buy any old crap!