Menu Fonts Size and Color

You could add some CSS such as the following into Appearance->Customize->Additional CSS

.main-navigation .nav-menu li a {
  color: red;
  font-weight: bold;
  font-size: 20px;
}

Adjusting the red and 20px values accordingly to your liking.

WOW! Thank you, that really popped. I used 24px and realized it did not affect the shopping cart and checkout numbers.
Looks a heck of a lot better just the same. We will wear them well.

You can use the following to target the cart section

.storefront-primary-navigation .site-header-cart a {
  font-size: 24px;
  color: red;
}