Custom colours in acrobat dc on ipad

I can't find a way to change the highlighting colour on my ipad to a custom colour like I can on desktop for Acrobat DC. Obviously you can change the opacity of the default colours but I can't pick my own colours like I can on my computer - the custom colour highlights I did on my computer show up that way when I view the document on my ipad but I can't adopt that highlight color or set any defaults which is annoying.

How can I add custom colours? If this isn't available on ipad yet, will it be soon?