i dunno man, 5v through a typical red LED (red usually being between 1.8 to 2.1v forward voltage ... a 6.8k resistor only lets through between 0.43 and 0.49mA
red is gonna want about 16mA on the low side... 0.5 will probably make it dimly glow...but not much.
not sure what kind of dealybop they got going in there ...maybe they have a multi chip LED or something... but even at 2 in parallel 6.8k is only 0.60mA
unless someone screwed up what resistor is actually in there but 220ish ohms should be about right for 5v
6.8k would be good for 115v (2.1v forward, 16.6mA current)
Your doubt is understandable. I had trouble believing it myself until I did some research and experimenting.
When I did my own current calculations, the GreenAntz LEDs were burning a unbelievably small amount of power, much less than 0.5mA. Yet they are/were lit and clearly visible, and I confirmed by measuring how much current was being used overall (essentially no change for adding the LED).
That's great because the units only draw around 85mA, keeps it below 100mA and well under < 0.5W
So, try it out yourself with some breadboard, or whatever works for you, and some different LEDs. The ones I'm using are common 3mm "bright" LEDs, ironically I make them fairly dim.
Honestly, those LED calculators are a bit misleading. The values they spit out are really the
minimum you should use to avoid burning the LED out.
There is no danger in using a higher value resistor, so long as it is rated for the power that will be running through it. If you are just going up in values, and for most arcade button LED applications, that isn't really a concern.
I've done a similar trick for a IKEA LED strip ("NOS") I'm using for a marquee light, though power rating was a concern there. The LED strip is the perfect size for the light bay, but much too bright (designed for installation under cupboards, lighting kitchen counters). It uses 24v and normally consumes 5.3W. So I did some math, applied ohms law, and settled on a 470R 3W rated resistor to limit the current. Now it is just the right brightness and consumes approximately 1W power.
That 470R 3W resistor is just barely warm after running for hours, days, because it is limiting the current and therefore the power consumption. Even though 3W is less than the original 5.3W, it is more than enough for the new 1W.
I wrote it up here.