Image caption color and text

This is the CSS that is adding uppercase (and the white caption text colour)

.wp-caption-text {
    color: #fff;
    font-size: 0.813rem;
    line-height: 1.2;
    letter-spacing: 1px;
    text-align: center;
    text-transform: uppercase;
}

So you would create custom CSS like this example:

.wp-caption-text {
    color: #000;
    text-transform: none;
    padding: 4px;
}

I also added a padding to it to give your caption some space around it, but you can remove it if you wish.

Great! This worked, thank you very much!!