The 40-year-old supermodel said that although things have improved since she started on the catwalk, black models are still not being used as much as they should be.
She told The London Evening Standard, "We're all aware that we need to introduce more women [of colour].
"But what I've seen recently is that I've seen it go backwards slightly. We need to raise awareness again and need to start using women of colour more."
And she said that she plans to take responsibility and raise awareness herself to help young models.
She explained, "It's not for myself, but the younger girls who come up to me and say, 'We didn't get used this season, we didn't do this, someone used 81 models and didn't use one of us'.
"In that respect if they come up and talk to me, and I'm able to speak on their behalf, then I will."