No - not everything needs to be colour toned in the same range - sometimes you should have a little extra. So why not adding a little piece of interest and climbing up the staircase will be fun. You will have a reason for making a little pause - LOL.
I love homes where you can discover small interesting bits and pieces everywhere. It is like going on a little discovery tour. Even if you have been a thousand times in your friends' home - isn't it fun to notice things which you haven't found before and you ask yourself "how on earth could I have missed that"?
The acrylic painting on the wall is Red Door from the Reminiscences series, a series that tells the story of a whole village which you can read here and here