It is associated with joy, sunshine, and tropics.  Orange represents enthusiasm, fascination, happiness, creativity, determination, attraction, success, encouragement, and stimulation.  To the human eyes, orange is seen as a very hot color, so it gives the sensation of heat.
West Virginia, Ohio, Illinois, and Indiana form the northern border  of Kentucky, along the Ohio River.
At issue was the location of the boundary between Ohio and Kentucky. The State of Ohio claimed that the boundary was the low-water mark on the northerly side of the Ohio River as it existed in 1792, when Kentucky was admitted to the Union.