As my daughter is not very interested in staying in bed we discussed a way on what makes here know what is still “sleep” time and whats “day” time. 

This is especially handy when sun is rising early and you still want to get some sleep.

Print front and back with some dark filamet and the middle parts with some diffusing translucent material.

I used two single WS2812B LEDs wired to an ESP8266 D1 Mini. I used ESPHome with following light config so i can control both LEDs individually while only using one GPIO Pin.

light:
- platform: neopixelbus
type: GRB
variant: WS2811
pin: GPIO4
num_leds: 2
id: "nachtlichtsonnemondled"
internal: True
restore_mode: RESTORE_DEFAULT_OFF
- platform: partition
name: "Sonne"
id: sonne
restore_mode: RESTORE_DEFAULT_OFF
segments:
- id: nachtlichtsonnemondled
from: 0
to: 0
- platform: partition
name: "Mond"
id: mond
restore_mode: RESTORE_DEFAULT_OFF
segments:
- id: nachtlichtsonnemondled
from: 1
to: 1

I also use the time integration to fade in and out

time:
- platform: homeassistant
id: homeassistant_time
on_time:
# Every morning on weekdays
- seconds: 0
minutes: 55
hours: 6
days_of_week: SUN-SAT
then:
- light.turn_on:
id: sonne
brightness: 80%
transition_length: 10min
- light.turn_off:
id: mond
transition_length: 3min
- seconds: 0
minutes: 50
hours: 19
days_of_week: SUN-SAT
then:
- light.turn_on:
id: mond
brightness: 17%
transition_length: 3min
- seconds: 0
minutes: 00
hours: 19
days_of_week: SUN-SAT
then:
- light.turn_off:
id: sonne
transition_length: 60min