Use horrible font colour to make them crazy (3,2,7)

I believe the answer is:

out of control

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'crazy' is the definition.
Both the definition and answer are adjectives. Maybe you can see a link between them that I don't see?

'use horrible font colour to make them' is the wordplay.
'font colour to' anagrams to 'OUT OF CONTROL'.
However, I'm not sure how the anagram is indicated.

Can you help me to learn more?

(Other definitions for out of control that I've seen before include "Unmanageable" , "Unrestrained" , "Frenzied" .)

I've seen this clue in The Irish Times.

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