A yellow LED needing around 1.9V (at 20 mA current) and with power source of 5V, needs resistor of at least 155 Ohm, implementing Ohms law:
(5V - 1.9V) / 0.02A = 155 Ohm
As 155 Ohm resistors do not exists, use 220 Ohm resistor instead.
Source (Ben Eater):
youtube.com/watch?v=CdqvY_vY1XA
