Etymology

Uncertain. Here are a few possibilities:

• 凊彩: From 凊 (“cold”) + 彩 (“good”) — “not good enough” > “cannot choose”.
• 靘彩: literally “dark or colourful” — it doesn't matter which you choose.
• 請裁: shortened from 請汝裁決 (“please decide”); this is unlikely.

Pronunciation