Have a look at f.lux, which alters your display's colour temperature as the time of day changes, shifting away from blues into the evening.
But neither of these has any point if you have blue light bleeding through from the LED backlight of the LCD screen. The most complete solution is OLED and a screen temperature adjustment like this.
iPhone's accessibility page for color filters looks like a clown car show of useless features. If anyone's found the magic configuration that makes that shitshow usable please share it.
1. You can set "reduce white point" to reduce white light 2. You can set a color tint filter and move the hue far to the left. That's the red/orange area. Set intensity to max. 3. You can set the accessibility shortcut to turn these on. (This one is lacking - it slows app switching on non-X devices)
I don't know how to assess actual colour spectrum output, mind you. Does this seem effective?
I leave night shift and true tone on as well.