If you’re still looking for help. Not exactly sure what you’re looking for.
Do you want to create a field to select a color and then use that color to change a font color?
Use a Color Picker field. This will allow the selection of a color then.
$color = get_field('my_color_picker_field');
?>
<span style="color: <?php echo $color; ?>;">My Text Here</span>
<?php
