Annoyed, Harry uncorked the poison he had taken from Siughorn’s desk, which was a garish shade of pink, tipped it into his cauldron and lit a fire underneath it.
There are no more uses of "garish" in the book.
Show samples from other sources
Outwardly, Annie showed no signs of garish ambition, but Mae was sure that there was something within Annie that insisted upon this, that she would have been here, in this position, no matter where she’d come from.
Dave Eggers -- The Circle
We did, and he swept the light over Martin’s body, a landscape of garish ruin.
Ransom Riggs -- Miss Peregrine’s Home for Peculiar Children