Navigate to Appearance → Customize → Body → Pagination to style the navigation that appears at the bottom of your list of blog posts, on your blog page. *Note - these settings will only apply if you have the 'Blog Pagination Style' set to Standard under Appearance → Customize → Body → Blog Layout.

Pagination:

• Align: sets the alignment of the pagination, it could be to the right, left, or center.

• Font Size: changes the size of the Pagination. You can use Pixels, em, or percentage %/
• Border Width: sets the border width of the Pagination numbers.

• Background Color: establishes the background color of the Pagination.
• Background Color - Hover: changes the background color when the mouse is over a Pagination number.
• Color: changes the color of the Pagination numbers.
• Color - Hover: modifies the color when the mouse is over a Pagination number.
• Border Color: sets the color of the borders.
• Border Color - Hover: modifies the boder color when the mouse is over a Pagination number