Starting with the jars we have the first standard to google. TO-43 is what we're looking at, when we hold the jars. TO stands for "twist-off" and the 43 stands for an inner radius of 43mm, round about 47,7mm of outside radius. 30ml is the volume of interest.
So I measured the jars and made two boards, first a display board which helps holding the orange/amber LEDs in place and solder them.
The second one is a base board for the display board with a ring for blue LEDs and a 74hc595 as the display "controller".
I spent about 40$ for the boards - had to order 6 of each because I needed 4 and OSHPark orders only come in 3-times batches. The resistors for the LEDs "driven" by the shift register are chosen to meet the max output current according to the datasheet. A first test showed that the 3mm LEDs will glow bright enough in scanning mode with a 265ohm resistor at 5V. A BC547 will control the led ring and also be able to be triggered with a PWM signal. The 3 by 5 led matrix leaves enough room for recognizable characters and numbers, as you can see here http://lineto.com/1.0/content_41.html
As soon as the boards arrive I will make a project out of it, but I feel bad for neglecting my other projects... I just love circular and stackable pcbs...
321 is minus
ABCDE is plus