Before I start trying to use CSS to style my buttons for hover - can I check that the out of the box solution using the "outline" option just doesn't ever allow you to set colours so the text stays visible? I haven't published my site yet so can't include a URL - am using a blank template and have tried a few of the custom color presets but not found any that don't apply the button border colour to the text and therefore obscure the text when they fill it on hover...