Change next/prev arrow color

Hi there

I have managed to change the background of the arrows by adding the following CSS code:

.wp-block-cb-carousel .slick-next:before, 
.wp-block-cb-carousel .slick-prev:before {
  color: red;
}

Now, how can I change the arrow color to red instead of its background?
It seems it is always transparent, but I cannot manage to change that.

Thanks in advance
Michael