Here’s a quick workaround plugin:
https://gist.github.com/squarecandy/036290389ba97434b17ab959a0ce9aef
Throw that in your plugins folder, activate, and then use sqcdy_acf_rgb('my_color_field')
in place of the_field('my_color_field')
or sqcdy_get_acf_rgb('my_color_field')
in place of get_field('my_color_field')
.
It just outputs RRR,GGG,BBB so you can use the output in your css like this:
color: rgb(<?php sqcdy_acf_rgb('my_color_field'); ?>);
or with rgba like this:
color: rgba(<?php sqcdy_acf_rgb('my_color_field'); ?>,0.5);