Add button-primary class to "Insert into post" button

[lessbloat]

In one of the ​user tests, the user didn't see the "Insert into post" button, and clicked the "Save Changes" button at the bottom instead (See 15:18 from that user test).

It would be nice, as a temporary fix to add a bit of contrast to the "Insert into post" button by changing the class to button-primary.

[lessbloat]

Shot of what it looks like after the change.

[Ipstenu]

Can 'Insert' be 'Save and Insert'? A bit of clarity means people won't think they have to save things and then insert.

[lessbloat]

Here's what "Save and Insert" would look like.

[isaackeyet]

I like the resolution, but it seems odd to me to have potentially a ton of "primary actions" on one page. It may work because it'll only show if the section is expanded, but I'd still prefer another way to highlight the function. Attaching a simple mockup of instead changing the background color to indicate "section toolbar" and provide focus on all possible options. Disregard buttons in the bottom, was playing around (unrelated).

[isaackeyet]

Sidenote: I think at the very least not aligning the insert button with the rest of the settings would actually help make it stand out and create that "sign off" feel.

[lessbloat]

Will no longer be an issue with new media layout/buttons.