CSS should work on all sites that use those templates:

/* Search box styles */

body #odysseus #OVExploreContainer {

    /* Default styles */

    –primary-color: #333 !important;

    –text-color: #fff !important;

    –secondary-color: #f5bf44 !important;

    –grid-col: 25% !important;

    –grid-col-num: 25 !important;

    /* Button styles */

    –ody-button-bg: transparent;

    –ody-button-border: var(–text-color);

    –ody-button-text: var(–text-color);

    /* Button hover styles */

    –ody-button-hover-bg: var(–text-color);

    –ody-button-hover-border: var(–text-color);

    –ody-button-hover-text: var(–primary-color);

    /** Form BG colour

        rgba([r], [g], [b], [transparency])

        e.g. 0,0,0 is black 255,255,255 is white

        or simply replace with a solid colour e.g.: #f00 **/

    –ody-form-bg: rgba(0, 0, 0, .25);

    /* Highlighted selections & dropdowns */

    –ody-highlight-bg: var(–text-color);

    –ody-highlight-text: var(–primary-color);

    –ody-highlight-hover-bg: var(–secondary-color);

    –ody-highlight-hover-text: var(–primary-color);

}

I’ve made it so you can just change the primary, secondary and text colours to change the whole form

You can then edit the other ones to make more precise changes