Is there some online tool that I can use to generate <s:RadialGradient> instead of having to do the whole thing like below
<s:GradientEntry color="0x000044" ratio="0" alpha=".5"/>
<s:GradientEntry color="0x00CC99" ratio=".33" alpha=".5"/>
<s:GradientEntry color="0xECEC21" ratio=".66" alpha=".5"/>
You could draw the graphic in Fireworks or Illustrator and then generate the FXG code from there. In Fireworks CS4 you would draw a circle, select a radial gradient fill and then move the color sliders around. Then select Commands > Generate FXG to save out an FXG file.
If you open that FXG file in a text editor you'll be able to see the code representation of the radial gradients you defined. Copy and paste from there into your Flex app.
I assume Illustrator has a similar process, but I have never used it.