Rash? It's nice and red, unfortunately (10)
I believe the answer is:
indiscreet
'rash?' is the definition.
(thesaurus)
'it's nice and red unfortunately' is the wordplay.
'and' is a charade indicator (letters next to each other).
'unfortunately' indicates an anagram (a bad or unfortunate spelling).
'its'+'nice'='itsnice'
'itsnice' put after 'red' is 'reditsnice'.
'reditsnice' is an anagram of 'INDISCREET'.
(Other definitions for indiscreet that I've seen before include "Reckless" , "Too ready to reveal secret things" , "Injudicious (anag of 6, 9 and 23)" , "shameless" , "Ill-judged" .)