If you like a visually consistent experience across PC n mobile, here's a theme using hex codes for the default colour scheme on Lemmy for desktop!
{ "monet_override_light_secondary_text_color": "#F1641E", "monet_override_light_primary_text_color": 0, "monet_override_light_link_color": "#00A846", "monet_boost_light_color": false, "monet_override_dark_secondary_text_color": "#3498DB", "monet_override_dark_primary_text_color": 0, "monet_override_dark_link_color": "#00BC8C", "monet_boost_dark_color": false, "monet_color_intensity": 0, "monet_manual_theme_color": "#303030", "monet_system": false }
It's in theming options. You have to choose manual to adjust some colour options.
Settings shortcut: Settings > Theme management
Actually, to be more precise, you need to copy all that code, then go to the Theme management section and choose load, then paste that code into the area that appears. That should then apply the theme. Just tested it and it worked for me.
Settings shortcut: Theme management > Load theme