The only states just north of Oklahoma are Colorado and Kansas. Kansas is East of Colorado, so that doesn't really fit the requirement.
However, if you remove the "just" from your requirement, then north of both Oklahoma and Colorado are Nebraska, North Dakota, and South Dakota.
Kansas.
Kansas.
Kansa
Kansas
The answer to this is Colorado
Kansas.
Colorado.
Wyoming is the state directly north of and on the northern border of Colorado. Nebraska is also north of Colorado, located on the north and east borders of Colorado. Montana is also north of Colorado as it is north of Wyoming. South Dakota and North Dakota are also north of Colorado as they are north of Nebraska.
Kansas
Kansas.
Kansas is due east of Colorado and due north of Oklahoma. Topeka is the capital city in Kansas.
Colorado is east of Utah.
Wyoming is the state to the north of Colorado. Colorado is a Rocky Mountain state bordered by Wyoming to the north, Kansas to the east, New Mexico to the south, and Utah to the west.
Kansas borders the east of Colorado.
The State To the west of Colorado is Utah. The state to the east of Nevada is also Utah.