Hello,

1) There is no such option to increase the font size of tooltip shown on the hover of variations. It requires customization and this is beyond our limitations and support policy.

2) To change the font size of SKU inside single product page. You can use the below CSS code inside global custom CSS are under theme settings:

.product_meta .sku {
font-size:20px;
}

Result: https://jmp.sh/JLObUPF

OR

If you are talking about the tab “SKUS AVAILABLE” inside your single product page. Then you can use the below CSS code to increase the font size of all those tabs:

.tabs-layout-tabs .tabs li a {
font-size: 25px;
}

OR

To just increase the size of “SKUS AVAILABLE” tab only use the below CSS code:

.skus-available_tab a{
font-size: 25px;
}

3) Normally when you hover over the swatch the color name appears in the tooltip. Unfortunately with theme current options the color name can’t be displayed on screen after “Color”. Actually when you used color then the color name goes hidden.

You can try the below CSS code at your own risk:

.woodmart-tooltip{
font-size:25px  !important;
padding-left: 30px;
}

.swatch-on-single:not(:last-child) {
margin-right: 15px;
margin-left: 50px;
}

Result: https://jmp.sh/oe06zHW

Best Regards.