Late to the show, but here is what I would do:
First off, it goes against standard to ask for a full name, so I would split up the
name field into
last name fields.
Second, I would match the colors to that of the app. I’d drop the border and replace it with a gray border with a subtle dropshadow. That teal should be your
action color, that way people know anytime they see that green, it is an actionable element (ie, buttons, filters, navigation, etc.)
Third, bring your font sizes up and make your fields a little bigger, this will make the form appear more friendly and inviting.
Fourth, make sure all the fields are the same size and distance apart, and make sure the form is centered.
I know I mentions this in a comment, but I’ll leave more detail down here over the placeholder vs label argument.
Here is my example of your recreated form as well