I have a series of checkboxes that when entered appear "flat", white
interior, blue border and when checked a green checkmark. On one of these I
wanted to have some type of highlight so I selected it and picked a color
from the  "Highlight" button in the "formatting" tool bar. Once I did that
the checkbox took on the "3D" effect with a black checkmark and the highlight
color I chose around it.

I would like the checkbox to look as it did originally with or without the
highlight. Although, even if I remove the highlight the checkbox stays the
same and I can find no way to change it back.

Is there any way to change the appearance of the the checkbox and checkmark?