I want better styling for inputs and selects

We all have been there: Designers want big, colorful checkboxes, radio buttons and selects. For the sake of accessibility it would be awesome if these elements could be styled with CSS in a better way. How often do we see something like *-appearance: none; and a circled :before. Or—slightly better—playing around with the height, the width and the opacity of the input. More accessible, but still a workaround. With the first solution these elements are not part of the accessibility tree—so make them fully tailorable.