Untitled

if (!empty($color_hex_2)) {
    $html .= '<span class="color" style="background: linear-gradient(135deg, ' . $color_hex . ' 50%, ' . $color_hex_2 . ' 50%);"></span>';
} elseif(!empty($color_hex)) {
    $html .= '<span class="color" style="background-color:' . $color_hex . ';"></span>';
} else {
    $html .= '<span class="color color__' . $color->slug  . '"></span>';
}