Now with Beta 5.0 there is Group Management.
There you can exclude a client by assigning to a group with no adlists and then pihole restartdns.
Would be nice if there was a status icon for each client on http://pihole/admin/groups-clients.php
Something like a red/yellow/green dot for no/partial/full blocking ads.
When you click on the green dot the client will be moved to the 'unassociated' group.
When you click on the red dot the client will be moved to the so called empty group with no adlists.
Yellow status has to be achieved by the user creating groups and adding clients to those groups. Is different for every Pi-hole user so can't be automated imo.
Edit: Maybe switching red and green as described above is more in line with how colors are used now (red for blocked).
My first thought was red for unprotected (danger).
@jfb
It's a fair point @DanSchaper makes.
How about to split this one as well as a general accessibility request?
There is more to accessibilty than colors. Alt text for pictures and font size for example.
My comment was mainly that any kind of functional use of colors needs to be accessible. We don't do that now, but the colors are informational so it's not quite a dire situation. Using colors so that you need to know the color to know what the button is going to do will need to be addressed.
General accessibility does need to be addressed in the project as a whole.
Instead of colored dots as I wrote in the feature request (colored) words or letters can be used.
My first thought was dots because UI space is restricted.