Hi,

By default, the WPBakery Page Builder doesn't have an option to select the custom colour of the Tabs, so please add the custom CSS code like the below to change to your colour:

.vc_tta-color-vista-blue.vc_tta-style-classic .vc_tta-tab>a {
    border-color: #69d294;
    background-color: #75d69c;
    color: #fff;
}
.vc_tta-color-vista-blue.vc_tta-style-classic .vc_tta-tab>a:focus,
.vc_tta-color-vista-blue.vc_tta-style-classic .vc_tta-tab>a:hover {
    border-color: #69d294;
    background-color: #5dcf8b;
}

For the transparent colour, please go to this page: https://rgbacolorpicker.com/, pick the custom colour then replace it with the code above.

Regards,
PenciDesign.