Since emails render mostly consistently with tables, many of the components are built into tables. These color classes apply to the current element as well as the child ≶td> so you can use it on a component it will still work if the component is compiled into a table.
Text Color
<p class="text-primary">.text-primary</p>
<p class="text-secondary">.text-secondary</p>
<p class="text-success">.text-success</p>
<p class="text-danger">.text-danger</p>
<p class="text-warning">.text-warning</p>
<p class="text-info">.text-info</p>
<p class="text-light bg-dark">.text-light</p>
<p class="text-dark">.text-dark</p>
<p class="text-muted">.text-muted</p>
<p class="text-white bg-dark">.text-white</p>
.text-primary
.text-secondary
.text-success
.text-danger
.text-warning
.text-info
.text-light
.text-dark
.text-muted
.text-white
Background Color
<div class="bg-primary text-white">.bg-primary</div>
<div class="bg-secondary text-white">.bg-secondary</div>
<div class="bg-success text-white">.bg-success</div>
<div class="bg-danger text-white">.bg-danger</div>
<div class="bg-warning text-white">.bg-warning</div>
<div class="bg-info text-white">.bg-info</div>
<div class="bg-light text-dark">.bg-light</div>
<div class="bg-dark text-white">.bg-dark</div>
<div class="bg-white text-dark">.bg-white</div>
.bg-primary
.bg-secondary
.bg-success
.bg-danger
.bg-warning
.bg-info
.bg-light
.bg-dark
.bg-white