How to create a curved color spectrum?

[Contours]

I'm trying to create a curved "spectrum" of color to use behind the numbers on a gauge.

I first tried a linear fill, going from green to red. It's easy, but it doesn't produce the yellow in the color transition.

Next, I tried placing swatches of colors and then using the arch as a mask ... but it would only pick up the solid colors, so there were no transitions.

Does anyone know of a method that might work? Is there a way to bend the staight color spectrum bitmap shown in the graphic?

Thanks in advance for any help.

[PhilM]

Hi Contours,

Draw your arc as a single shape and then use a conical fill from red to green and set the fill effect to "Rainbow" to make it transition through yellow.

Phil

[handrawn]

if you want more control you can add more handles to the fill line curve

you could also use a blend to a blend [to a blend... the more blends the more colour control] - and then fit blend to curve - but Phil's way is simpler

[Contours]

Thanks for the suggestions. I was able to get exactly the result I was after by using 3-color Simple. Here's a snapshot for anyone who might find this thread.

I appreciate your help.