Prepare The Tools and Materials
To make things clear, I've taken a photo of all the electronic components placed nice and tidy.

i) Electronic Components:
Logic DC Jack (Mainboard) from Techbox Tricks ×1
Grove – Universal 4 Pin Buckled 20cm Cables ×2
Grove – Light Sensor ×1
Grove – Infrared Emitter ×1
9V to Barrel Jack Adapter ×1
9V Battery ×1
ii) Materials:
Paper Cup ×2
Wadding
iii)Tools:
Glue Gun ×1
Utility knife ×1
Steps
Step 1 Connect the light sensor, colorful light and battery with the logic DC jack using cables.

Step 2 Cut a small rectangle hole in the bottom of the cup.

Step 3 Fix the logic DC jack module in the hole with glue gun.

Step 4 Fix the light sensor on the edge of the cup with glue gun.

Step 5 Make one more cup as steps above, and put some wadding into them.

Finally, the light pouring cups are completed and you can pour light from one cup to the other.

Future Work
We want to make a series of light pouring cups in the future. We can pour one cup's light into another. The first cup will be empty (dark) and the second one will light up at the same time.