custom CSS possible to change the colour of the full stop '.' in header?

Hi

I downloaded a fresh wordpress installation enfold gymn theme

I like the OUR TEAM. with OUR TEAM in black, and the full stop in red.

In other words, the ‘heading text’ has 2 different colors, the full stop is always black

(I have 36 other pages to do in the same way)

The demo site uses a ‘special heading’ element
The ‘Heading Text’ is:
Our Team.

Underneath is a warning in red:
Warning: Characters <,>,[,] might break ALB backend or frontend. Read more if you want to use them. You can use valid HTML markup.

To summarise:
The demo sites uses a tag that causes a warning.

I am in touch with a developer asking him if he can do a custom CSS to replicate this, and he feels it might not be possible.

*** The issue is that I’d like to do best-practice rather than add code directly in the Advanced layout editor element ***

Is custom CSS possible, do you have a steer on how my developer could go about this?

Thanks

Richard