Old retired volunteers with tea, say, being pale brown (7)
I believe the answer is:
oatmeal
'pale brown' is the definition.
(I've seen this before)
'old retired volunteers with tea say' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'retired' shows that the letters should be reversed in order.
'volunteers' becomes 'ta' (abbreviation for Territorial Army).
'with' says to put letters next to each other.
'tea say' becomes 'meal' (tea is a kind of meal).
'ta' in reverse letter order is 'at'.
'o'+'at'+'meal'='OATMEAL'
'being' acts as a link.
(Other definitions for oatmeal that I've seen before include "Porridge constituent" , "Ground grain used to make porridge" , "Kind of porridge" , "Porridge ingredient" , "Source of biscuits" .)