Carousel slider h4 capacity

Hello.

1. When i customize theme’s color the h4 header in carousel slider loose its opacity.
I tried to change it in CSS:

.carousel-caption h4 {
background: #36d7b7;
background: rgba(54, 215, 183, 0.5);

But it doesnt work.

How can i return opacity to carousel’s <h4> for my color?

2. And carousel’s <h4> and <p> don’t see in iPad in vertical mode.

Thank you for you answer.
BR, Ruslan.