Devotion feats:

[Greenish]

To take a Devotion feat one must already have the domain selected as one of the two/three domains given and THEN "sacrifice" that domain for its corresponding Devotion feat?

For example to take Strength Devotion you must already have the Strength Domain and then give it up for Strength Devotion.

You can do that, or you can just pick them up as normal feats. Most of them don't even have any prerequisites.