Sharepoint conditional formatting not applying to item view

Hello,

I require some help with a sharepoint list that I have setup to track issues. I have a column that has a priority label: Low, Medium or High based on a number value. 

I have setup a conditional formatting see below in list view:

However, this conditional formatting does not show in the item view see below:

Is anyone able to tell me why and how do i correct this?

Many thanks