As Ashen has posted before me, you've either accidentally drawn on the base lines, had low opacity and they show through, or just forgot to delete the layer. To delete the UV lines, right click on the layer and click either "clear" or "delete".
To delete the UV lines, right click on the layer and click either "clear" or "delete".
Popping back in here as a reminder that you can just hide the layer incase you need it later on.
CTRL+L then click the little eye icon to hide that layer.