RGB led only works when the green light is on

i bought rgb led , specs

30ma (green/blue), 50ma (red)
3.5v typical, 4.0v max (green/blue); 2.0v typical, 2.6v max (red)

i running basic tests seeing if worked day before , working ,(forgot use resistor, lights getting 5v arduino uno)
i tried see if have multiple colors on @ once , worked ,
then today when tried turn on each color seperatly wouldnt turn on,
but when tried turning on multiple colors works when green , color turned on.
(this time tested , without resistor)

1.) need resistors. no resistors = killing led , arduino board
2.) need 3 resistors rgb led, 1 each color.

using single 'shared' resistor doesn't work.

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