I've searched for this topic, read some answers and tutorials but haven't found a solution.
Basically, I want to roll over the image, or link block, and have the image change to a color overlay. I think the wrinkle here is that I have a link block and don't use a background image.
Here's the organizational breakdown
flex-item is a container
link block points to a project web page
image is a thumbnail of the web page project
flex-item-title is the name of the project
flex-item > link block > nightbird.jpg > Nightbird