How do you change the color of the duplicate item in a new layer?

[AntDX316]

I have Left Line in Layer 1 as Color: Red.

Right Line in Layer 2 as Color: Red.
I want to change the Right Line in Layer 2 as Color:Red to Color: Green.

The lines aren't "solid" so you can't just select it and paint over. It has some Feathering. How do you do it? Besides painting over with another line of another color the same way then deleting.

[Chuck Uebele]

Put a solid color fill layer, above the layer you want to change color. Set the color that you want, and clip the fill layer to the layer you want to change by holding the alt/opt key and clicking between the two layers in the layer panel. You can then merge them, if you want to.

[Stephen_A_Marsh]

Another option would be a clipped hue/saturation adjustment layer or simply running hue/saturation directly to the layer.

[jazz-y]

just lock transparency, then paint on layer