IonButton - Single color button

When I create an IonButton, the button gets created with two colors. One for the button background and one for the background of the text. I’ve searched the web and followed several methods to have the button with a single color (or alternatively, having the label color be the same as the background color). I’ve also tried controlling it with CSS. No methods have been successful.

Any idea how I can have a button with a single color?

loginbutton