Yes. Go with darker.
To take a closer look at what was happening I took a crack at Popka based on the Moogle Sprite with a 20 minute limit. It's been years since I've sprited anything.
There were some spots where the outline was definitely too thick. I culled some bits back, especially at the corners.
I darkened the shadow color and added another " mid " color for the fur and bandanna to give it some depth.
Outlined the feet and the bandanna with black to match up with the Moogle Sprite.
Fixed the nose since it was bothering me.
Woud've fixed the ears if I had more time. Not happy with them.
Wasn't sure what was going on with his left arm so I redrew it. In retrospect, it should probably be raised and pointed forward.
Made the pink sections darker and gave a shadow to his eyes to give them some depth.
For the Moogle Sprite I noticed that it was outlined black around the exterior, but the interior used it more sparingly mostly to define the features of the body. For the first set maybe less black on the interior and more darker colors to define those shapes.