I am no good at this

No matter how many hours of HGTV I watch, I will never be good a decorating.  I have managed to do things in my house little by little, but now I am stuck on my master bedroom.  Other than move furniture in and out, we haven't done anything with this room since we moved in 3 1/2 years ago.  My mom made us a beautiful quilt when we got married that was the one bright spot in our room. 

In my redecorating planning, I decided that I want to go with some different colors for our room.  I wanted brown walls (we get TONS of natural light) with green accents.  I found a bedding set I thought was perfect so I bought it.

While I still like it, now my lack of designer-ness is causing me stress.  Since I have taupe bedding, can I still paint my walls brown? I was hoping to do tan walls with a dark brown accent wall around the bed.  Would that be too many colors of brown?  Would I be better off painting the room green and going with brown curtains for this window?

Can I paint it green, even if 3 other rooms in my house are green (1/2 bath, laundry, nursery)? Or should I stick with the brown paint and do green curtains? I bought some off white curtains with the intent to sew a band of green fabric at the bottom.  Of course, when I went today, the store no longer carried the fabric I wanted! 

I think once I have the paint and curtains figured out I'll be able to do the rest.  But for now, I'm wishing David Bromstead could swing by and give me some tips!