JSFiddle - React, Tailwind, and code Playground

HTML

<table>
                    <tr >
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
                                    <td class="cell cell-hotel-border" ></td>
             ...

CSS

html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed, 
figure, figcaption, footer, header, hgroup, 
menu, nav, output, ruby, section, summary,
time, mark, audio, video {
	margin: 0;
	padding: 0;
	border: 0;
	font-size: 100%;
	font: inherit;
	vertical-align: baseline;
}
/* HTML5 display-role reset for older browsers */
article, aside, details, figcaption, figure, 
footer, header, hgroup, menu, nav, section {
	display: block;
}
body {
	line-height: 1;
}
ol, ul {
	list-style: none;
}
blockquote, q {
	quotes: none;
}
blockquote:before, blockquote:after,
q:before, q:after {
	content: '';
	content: none;
}
table {
	border-collapse: collapse;
	border-spacing: 0;
}

.cell {
    width: 5px;
    height: 5px;
}

.cell-hotel-border {
    background-color: #0078a3;
}
.cell-hotel-empty {
    background-color: #009ceb;
}


.cell-building-empty {
    background-color: #313131;
}
.cell-building-border {
    background-color: black;
}

.cell-room-empty {
    background-color: #915608;
}
.cell-room-border {
    background-color: #356635;
}

.cell-black {
    background-color: #000;
}
.cell-red {
    background-color: red;
}

JavaScript

$(document).ready(

    function() {
        var color;

        $(".cell-hotel-empty").hover( function () {
            color = $(this).css('background');
            $(".cell-hotel-empty").css('background', '0');

        }, function() {
                $(".cell-hotel-empty").css('background', color);
        }
        )
    }
)