How do you add a custom border

I'm trying to add a custom design to border each page of our site but haven't been able to track down a code. Any help with this is appreciated!

@Booch1 Can you share link to your site? Difficult to help without info

5 minutes ago, Booch1 said:

icarotea.com

 

pass: 12345

Add to Home > Design > Custom CSS

body#collection-5deff5eb684f0b4f52631978 .Site {
    border-color: red;
}

Replace body#... with Page ID. Each page will have different ID. See my signature to know how to find Page ID.

Cool, thanks! And how can I add a custom design that isn't a color that Squarespace provides?

8 minutes ago, Booch1 said:

Cool, thanks! And how can I add a custom design that isn't a color that Squarespace provides?

I don't understand your question "custom design that isn't a color that Squarespace provides"?

"custom design"?

Which color SS doesn't provide? 

Like a pattered custom design our designer made

12 minutes ago, Booch1 said:

Like a pattered custom design our designer made

try: border-image: url(paste border image url) 30 round;

Cool! Thanks so much!