Error in Forms Designer - Button Color doesn't change

Dear Support Team,

i created a form with your template library and modified it with the designer afterwards.

https://form.jotform.com/53262327583962

However, i can't modify the color of the submit button. For whatever reason it stubbornly keeps beeing black instead of a color i select in the designer. 

Even modifying the code in the CSS didn't change anything.

What in gods name, do i have to do, to modify the color of simple a simple button?

Please tell me how to do that. I wasted 4 hours with jotforms and i am close to leaving. 

To adjust the background color of the submit button you may inject the following CSS code:

.form-submit-button {

    background-color : blue !important;

}

If you require additional assistance, please let us know.