Images as checkbox values

I want to be able to include a membership logo for participants who are members or certain organizations. Ideally, it would be a multiple checkbox field (or separate radio button fields would be okay) and the value would be an image.

I would love to do with css, but when getting it to show ONLY when the value is present doesn’t seem to be working. This is what I used:

td.myfieldname-field[value=”field value”] {background: url(my-image)}

but it doesn’t work. I tried value “true” also.

I would appreciate any help you can give me. Thanks!

https://www.ads-software.com/plugins/participants-database/