Edit in JSFiddle

<p class="class1">Affected by class 1</p>
<div class="class1">Affected by class 1</div>
<p class="class2">Affected by class 1</p>
<div class="class2">Affected by class 1</div>

.class1 {
    color:Red;
}
.class2 {
    color:green;
}