Traditional window colors have springs and an anti-reverse mechanism inside the roller. Over the years, the spring may loose tension, along with the roller does not draw the shade fully up. When this occurs, you just rewind the roller to increase the spring’s tension. In most cases, you’ll have the shade operating like new in a matter of minutes.
Pull down the shade, and permit that the anti-reverse mechanism to catch. Work from a stepladder, and lift the roller from the brackets at each end. If the shade is fully drawn, lift the roller from their brackets, and lay the colour onto a level surface.
Grip the roller near each end, and roll up the shade evenly onto the roller. If the shade was fully drawn, roll it halfway onto the roller or you might raise the stress too much.
Insert the square hints at each end of the roller to the slots on the corresponding brackets. Pull down the shade, and gradually release it so the anti-reverse mechanism catches. Pull down the colour to publish the mechanism and increase the shade up all of the way.
Duplicate the rewinding process in the event the shade rises too gradually for your preference.