Fix button color setting in admin

Commit 8a4f3f2b, 08/04/2022

/app/code/Blueskytechco/Themeoption/view/frontend/templates/css/theme_option.phtml

/app/design/frontend/bluesky/bluesky_default/web/css/source/_custom_default_extend.less

/app/design/frontend/bluesky/bluesky_minimog_default/web/css/source/_custom_bluesky_extend.less