- Add the following code to the bootstrap Custom CSS of the Company:

/* Blocks Tab  */
.ep-product-blockfields .ep-page-tab {
    text-transform: uppercase;
    font-weight: bold;
}
.ep-product-blockfields .ep-page-tab a {
    color: red !important;
}

.ep-product-blockfields .ep-page-tab.active a {
    color: green !important;
}

OR

- You can add same code to the the actual product layout CSS.