colors and toggle

please why is there no option to change the board color? my eyes hurt, I need more of that dark MODE in my life, I even painted my rooms walls DARk. I wear sunglasses during the winters. a background with cool texture or lines like its a piece of paper would be cool

also, can you add a feature where I can toggle hide and expand things that connect to a main item, the feature to collapse. This is is useful to make things look cleaner or use as a flashcard type thing for mindmaps