Вы можете просто сделать это в css: .calCell:hover
Подробнее о :hover
: https://www.w3schools.com/cssref/sel_hover.asp
.calCell {
background-color: rgba(255,228,196,0.1);
font-family: JMH Arkham;
font-size: 50px;
color: khaki;
text-shadow: -1px 0 black, 0 2px black, 2px 0 black, 0 -1px black;
width: 70px;
height: 70px;
border-color: rgba(176,196,222,0.2);
}
.calCell:hover{
color:red;
}
<tbody>
<tr>
<td><button class="calCell">01</button></td>
<td><button class="calCell">14</button></td>
</tr>
</tbody>
Соответствующее значение:
.calCell[value="14"]:hover
и добавление к кнопке <button class="calCell" value="01">01</button>
.calCell {
background-color: rgba(255,228,196,0.1);
font-family: JMH Arkham;
font-size: 50px;
color: khaki;
text-shadow: -1px 0 black, 0 2px black, 2px 0 black, 0 -1px black;
width: 70px;
height: 70px;
border-color: rgba(176,196,222,0.2);
}
.calCell[value="14"]:hover{
color:red;
}
<tbody>
<tr>
<td><button class="calCell" value="01">01</button></td>
<td><button class="calCell" value="14">14</button></td>
</tr>
</tbody>