Creating half a rainbow

[malesxa_62523989]

Hello- I am having sever trouble trying to recreate a logo. All I need help with is the recreation of this bottom arc. I've tried just drawing it with the pen tool but cant seem to get it perfect. Can anyone help? Not sure why this one is so baffling to me! 

[macpawel]

try you use (in theis case) classic rectangles to prepare Art. Brush and then use this brush to prepare shapes. Finally you can also try to use Width Tool to change width of this strokes

[Ton Frederiks · Accepted solution]

You can use a blend to get the paths.

Create a curved path, copy it and scale and adjust it to get a second path with the same number of anchor points.

Make a blend, expand it.

Use copies to join the end points and fill with color.