these decisions do not lie in realm of what's in style or will be in style

they depend on you and your personal reaction to colors

tone on tone can be beautifully done..harder to pull off than color, at least to me, since I'd be one for example dying to try tone on tone, and then it wll lbecome not enough stimulation for me, and I'd start adding color..then another one..then another one..

I can admire it deeply when done right(and "done right" will presume you'll need shades of colors..subtle variation..and a lot of different textures to bring depth, or it won't be good tone on tone)

but I'm not sure I'd be able to really commit to it, because that's not me. I admire it,yet it's not me.

so I presume you'll get different answers-and it will be more about other people than about you

while it should be about you

start figuring it out. what works for you the best? what is the vibe you're going for?

when you buy bedding-start neutral..that way, you can always mix it up more later. and also you can buy another set later if you decide you need more color. There's no rule it should always be same bedding, same coverlet, etc.

Try to bring in things that have texture..say a throw that is always handy..a pillow..plants especially if your room gets enough light..layers of lighting

as you go notice your reactions..give yourself some time too..if iit makes you happy-continue..if you feel restless and irritated-it might mean you crave more color

we're all different.

don't hurry..good rooms take time. whether they are mostly monochromatic, or full of color, or anything in between.