Turning pale when aunt oddly caught husband wearing flashy jewellery (9)

'turning pale' is the definition.
('blanch' can be a synonym of 'turn pale')

'aunt oddly caught husband wearing flashy jewellery' is the wordplay.
'oddly' indicates alternate letters (letters in odd-numbered positions).
'caught husband' becomes 'ch' (this might be a standard abbreviation of which I'm unaware).
'wearing' means one lot of letters goes inside another.
'flashy jewellery' becomes 'bling' (I've seen this before).
The alternate letters of 'aunt' are 'an'.
'an'+'ch'='anch'
'anch' put inside 'bling' is 'BLANCHING'.

'when' acts as a link.

Can you help me to learn more?