E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Chameleon.
You are a chameleon, i.e. very changeableshifting according to the opinions of others, as the chameleon changes its hue to that of contiguous objects.
1
As the chameleon, who is known
To have no colours of its own,
But borrows from his neighbours hue,
His white or black, his green or blue.
Prior.
Pliny tells us that Democrtus wrote a book on superstitions connected with the chameleon.
2
Cest un cameleon. One who shifts his opinions according to circumstances; a vicar of Bray.
3
To chameleonise is to change ones opinions as a chameleon changes its colour.