Louvered wooden vents painted same color as the trim. What about a mortar wash over the block. No advice on the blue pool paint since I am not familiar with the product. With that in question, you could use copper sheeting to cover the blue area. In a previous house, we purchased a thicker copper sheeting from our HVAC company for backsplash and hood vent. You can patina before installation by wetting several times, allowing to dry in the sun between wetting.

Thank you! That is a great idea and a quick and not expensive fix (for now). I'll check out primers. I wasn't aware of anythat went over epoxy.

I also like the louvered look. Not sure how to cut it at an angle to fit the triangle shape though. I'm sure my "handyman" (hubs) could though.

Adding the copper would look really cool. You wouldn't need to cover the entire front space with copper sheeting (not sure how expensive that would be) - you could just use a piece of copper as an accent with a dark surround (painted - or a tinted concrete that could be added over all of the blue - or all of the blocks). Many people have done diy skim coating of cement/concrete over brick (for example, on fireplaces):

For color only:

OOoooo I like that idea. I will have to look into that. Copper can be costly and we have never worked with it before.

Our builder built the louvered sections in their shop, then installed onsite.