How to fill all selections at once?

I need to select all the red areas in an image and replace them with a particular orange in one click.

So I have clicked on MASK  > COLOR MASK (just using the magic wand tool only selected one red area, not all)

Then I used the eye dropper to select the color I'm after. Now all the red areas are selected. Good so far.

Then I chose the fill tool and clicked on one of the red selections, thinking that ALL the selections would fill with my new color, but NO. Only the one I clicked on turned orange.

Is there a "contiguous" button that I can turn off? I need to fill all the red areas with one click.

A solution to this would REALLY help me out!