The singer unveiled her new look earlier this week, and it is believed that her decision to go blonde was inspired by Ashley's love of ladies with golden locks.
A source told The Sun, 'Ashley had a lot of input with the new hair. He said it would suit her. Everyone knows that Ashley goes for blondes.'
The couple are thought to have reunited after divorcing last year amid claims that the footballer had been unfaithful.
Cheryl, 28, has kept a low profile since being dropped by the US X Factor but will celebrate her 28th birthday with a posh bash tonight, Friday.
'She is preparing to step back into the limelight,' added a second source.