Check out this excellent Kitronik programmable alarm clock kit for the micro:bit - with multicoloured LEDs, real time clock, battery backup, and sound! There's no soldering so this can be programmed with drag 'n' drop blocks (MakeCode) - suitable from ages 8 upwards, or with MicroPython for older people.
The detailed instruction booklet and online tutorials, provides plenty of room for creativity, with 60 multicoloured LEDS that can vary in brightness, a microphone for sound detection, and audio for customisable alarms or other events.
Use this kit to add some new life to vintage clock cases, or create your own with 3d printing.