Change background colour of Ionic 2 Item Divider

Does anyone know how I can change the background colour of an Item Divider in an Ionic 2 app?

<ion-item-divider>
 My Category
</ion-item-divider>

Whatever I try, the divider always has a blue (i.e default Primary) background ?

Can you paste your code into codepen ?

Well, I’m not exactly sure how to specify the colour so I don’t have any code to share.

I would have thought I could do something like:

<ion-item-divider secondary>
 My Category
</ion-item-divider>

but it doesn’t work?