Are you valid? Yes.

I doubt a description is necessary.

A mockingbird.
This little bird is blue.
Blue.
Blue is the colour of...
...the sky.
A mockingbird flies.
Flying is in the sky.
A mockingbird is valid.

A violin.
Are you brown? It appears that you are.
Brown.
Brown is the colour of...
...fecal matter.
A violin is not fecal matter.
It has strings, for instance.
A violin is not valid.

A cup of tea.
You are, perhaps, beige.
Beige.
Beige is the colour of...
...peanuts.
A cup of tea is not a peanut.
It is, however, peanuts.
A cup of tea is valid.

We!
Are all valid.
In our own way.
Apart from a violin.
A violin is not valid.

A violin is NOT valid.