Adding a colored outline/border to a wonky shape

[owlshockey]

Hello!
I have NO idea how to do this, and you should know I've never used photoshop before so please explain this as if to an idiot if possible lol.
I would like to add a border to this image:

Sort of like the yellow one here (but in the FAU red):


Thanks to anyone who attempts to explain this to me, and I apologize in advance for when I don't get it the first time around.

 

[prd]

edit -stroke

 

[owlshockey]

haha woah, that just shows what a newbie I am... thanks so much I did it!

 

[Paul]

Do it twice and you get a richer colour effect

 

[owlshockey]

Thanks, I will try it! Should both of them be the same width?

 

[Paul]

Just duplicate the image and make the second a overlay or soft light (depending on your taste).

soft light version