I'll bet the grey stuff is the best of the lot: it's got sticks between the boards indicating its been properly seasoned.
C16 is perfectly fine where it's man enough for the job ( eg a 7x2 C24 won't work but 8x2 can work as C16 without needing C24)
Danage is another thing entirely: I would be looking to get some replacements but most of it's fine. None of it's new don't forget, it's been a tree in a previous life!
This new 9x2 is 34% moisture content
this 4x2 is 31%
This 9x2 is 17%
And the coloured timber is between 13-16% moisture content. And this is on the outside. Maybe inside timbers even less.
