16 ultra bright smart LED NeoPixels are arranged in a circle with 1.75" (44.5mm) outer diameter. The rings are 'chainable' - connect the output pin of one to the input pin of another. Use only one microcontroller pin to control as many as you can chain together! Each LED is addressable as the driver chip is inside the LED. Each one has ~18mA constant current drive so the color will be very consistent even if the voltage varies, and no external choke resistors are required making the design slim. Power the whole thing with 5VDC and you're ready to rock.
The NeoPixel is 'split', one half is the RGB you know and love, the other half is a white LED with a yellow phosphor. Unlit, it resembles an egg yolk. Lit up these are insanely bright (like ow my eye hurts) and can be controlled with 8-bit PWM per channel (8 x 4 channels = 32-bit color overall). Great for adding lots of colorful + white dots to your project!
NeoPixels are 5050-sized LEDs with an embedded microcontroller inside the LED. You can set the brightness and color of each R/G/B/W with 8-bit PWM precision (so 32-bit color per pixel). The LEDs are controlled by shift-registers and only 1 digital output pin are required to send data down. The PWM is built into each LED-chip so once you set the color you can stop talking to the ring and it will continue to PWM all the LEDs for you.