Changing the colour scheme to high contrast colours can help improve legibility and make it easier to use the menus. You can change this in the settings menu:
Bring up the menu on your remote
Select Settings*
Scroll down to the Accessibility & Language area and select Appearance
Select High contrast colours
Change this to On
Select Done
*Settings can be found via the cog in the top right corner of the Menu. You can get to the cog by pressing Up and right after opening the Menu.