This is an example of an oxymoron.
An oxymoron is a word or a group of words that is self-contradicting, for example bittersweet ( neither bitter nor sweet ).
The terms comes from Greek where it means 'pointed foolishness'.
This rhetorical device is often used to reveal a paradox.
Dark with excessive bright is an oxymoron because the adjective dark contradicts the adjective bright.
