You can use this in the CSS file:
Code:
.color1 {
color: #FF0000;
}
.color2 {
color: #00FF00;
}
.color3 {
color: #0000FF;
}
Then designate the parts you want to have a different color:
<p> ... </p> will be default.
<p class="color1"> ... </p> will be red.
<p class="color2"> ... </p> will be green.
<p class="color3"> ... </p> will be blue.
If this works in Calibre's preview, then you have done everything correctly; if it doesn't work in Moon Reader, it may be ignoring font colors.