Basic CSS: Use RGB to Mix Colors

<style>
.red-text {
color: #000000;
}
.orchid-text {
color: #000000;
}
.sienna-text {
color: #000000;
}
.blue-text {
color: #000000;
}
</style>

<h1 class="red-text">I am red!</h1>

<h1 class="orchid-text">I am orchid!</h1>

<h1 class="sienna-text">I am sienna!</h1>

<h1 class="blue-text">I am blue!</h1>