quiz of quizzes

[jerrymouse]

One more bothering me in a cryptic-type quiz, where the answer must begin with I. Many thanks in advance.

Colour of Cockney estuary (5)

[gen2]

(H)umber

[gen2]

What makes you think it starts with I? Clues that refer to Cockneys generally mean a dropped H. What is left now has to be a colour. Don't think I can also make it start with I. Sorry.

[Scarletta]

I go for Umber as well