For a first Build and Proof of concept i took an APA102C LED Strip and sliced a wooden circle using a jigsaw.

The Proof of concept was used to test the "brightness and capability of those LEDs" as Brightness needs to be Top-Notch.

As the GIF-Image shows, the overal Colors where quite bright, but a  White only or mixed white color does not seem to be useful for the clock display.

#Questions:

1. Is this build possible with homemade materials?

2.Can this Clock use Colored LEDs?

3. How much Hardware can be embedded in the "Frame"?

Video of Test-Circle:

#Answers:

1. Is this build possible with homemade materials?

--> Yes, it can be easily build, important are the correct measurements and "distance between the LEDs to have a good and clear-Image/display!

2.Can this Clock use Colored LEDs?

--> Yes/No Coloured LEDs bring the benefit of having different Display-Types, but the Brightness lacks a lot.

As conslusion i will go with WWA (WarmWhite/White/Amber)-LED strips

3. How much Hardware can be embedded in the "Frame"?

Depending on the Spacing the place for Hardware in the Frame is limited.

So the basic hardware in Frame will be limited to an ATTINY85, A DCF Antenna for Clock-signal, a PIR-Element and the LEDS.

The Rest of the Logic will be In the "PowerSupply/Control-Box".