Donald's expression of impatience about yellowish hue (5)
I believe the answer is:
ochre
'hue' is the definition.
(ochre is a kind of colour)
'donald's expression of impatience about yellowish' is the wordplay.
I cannot quite understand how this works, but
'of' could be 'o' and 'o' is found within the answer.
'about' could be 're' (common abbreviation for 'with reference to') and 're' is found in the answer.
The remaining letters 'ch' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ochre that I've seen before include "Yellow-orange colour" , "Light yellow-brown colour" , "Yellow-orange hue" , "natural colouring" , "yellowy-orange" .)