I use the plugin “CookieYes” by CookieYes (WebToffee). Add the following code to the CSS file.
#cookie-law-info-bar{background:RED!important;border-top:2px solid GREEN;}
.cli-bar-message{font-family:andika;}
.cli-tab-footer .wt-cli-privacy-accept-btn,.wt-cli-element.medium.cli-plugin-button.wt-cli-accept-all-btn.cookie_action_close_header.cli_action_button,.medium.cli-plugin-button.cli-plugin-main-button.cli_settings_button{background:BLUE!important;color:YELLOW!important;font-family:andika;text-transform:uppercase;font-weight:700;}
.cli-tab-footer .wt-cli-privacy-accept-btn:hover,
.wt-cli-element.medium.cli-plugin-button.wt-cli-accept-all-btn.cookie_action_close_header.cli_action_button:hover,
.medium.cli-plugin-button.cli-plugin-main-button.cli_settings_button:hover{background:PINK!important;color:BLACK!important;}
table.cookielawinfo-winter thead th{background:PURPLE!important;}
.cli-modal-content{background:WHITE;}
.cli-modal-content h4{color:BROWN;font-family:andika;}
.cli-switch input:checked + .cli-slider{background:RED;}