So my house is out said city limits but in kinda a residental area. The houses arent on top of each other but i ant in bfe. A bunch of deer like to walk across our property. I was thinking about getting a bow and setting up in the back yard or better yet on my 15 foot high deck ad it would be nearly a vert shot so no risk of the arrow leaving my property

Im in Colorado so id like some people who know colorados law better then me to answer

Depends on the county. Laws vary accordingly. Also, you don't say how big your property is. If it is an average residential plot (less than an acre) that could compound it even if it is legal.

Personally, I wouldn't do it unless I know for a fact that none of the neighbors would object. You may be able to keep the arrow from leaving your property but how would you stop a wounded deer from leaving. You could double lung one and have it run better than a hundred yards and die in someone elses yard or out on a public road. And if any of the neighbors are an anti-hunter you would have hell to pay.

Feel free to disagree if you want but that's how I see it based on the info you have provided.

You are asking the wrong people. Your local LE (Sheriff's office, Conservation Officer, etc.) will be happy to answer your question. Ask these people before you do it, as you almost certainly will be speaking with them later.

Even if it is legal, what are you going to do when the deer runs away and dies in a neighbor's yard? Deer shot with an arrow seldom die right where and when they are shot.

Do you have a tag?

Well i ant shootin one with out a tag I thought bout it and recovering it lead me to so its a bad idea

Your grammar is so poor in this post, it's hard to read.

Yep same as the others have said ask a legal enforcement agent DNR or county sheriff. Better to be safe rather than sorry and sued or jailed.
Good luck hope it all works out for you.