How a (different) LCD backlight would look on your RC transmitter? Here's one sample of common samples (normal and inverted).
According to wikipedia, rhodopsin is a biological pigment in the photoreceptor cells of the retina, responsible for low light vision. It is highly sensitive to green and blue light, bleaching very fast. It takes up to 45 minutes to regenerate.
Thus, if you want to fly in night mode, an inverted red LCD display would be the best option for your RC transmitter. Unfortunately I haven't found one for the Turnigy 9x transmitter yet.