Help with curved lines and shading

[Psaumure]

Is there anyone that can help with curved line shading? I'm trying to duplicate this sphere on the right with the lines that are going around the sphere. I am having problems getting the shading to follow the line around the bends. Currently I have three different color lines that I have blended. Using the blended lines does not give me a uniform thickness throughout the bends. Is there a technique to bend a line and hold the gradient shading? Any suggestions or help would be greatly appreciated.

[Giovanni]

Kind of driving off-road here, but in a difficult case like this I would make the sphere and the tube in real 3D with Blender, and thereafter would paint over missing details if any.

Xara is powerful, but realistic 3D with reflections is a totally different field.
You'll get much more quick, easy and precise results with a dedicated 3D software, that's for sure.

Keep up posted on this picture, is an interesting challenge.

[MarkMyWords]

This is how I would do it.

By disecting the .xar file you can see that

1/I started with a basic line

2/copied that - Ctrl+C

3/Converted the base to a shape - Menu -Arrange/Convert line to shape. Then adjusted it to fit the sphere.

4/I pasted the copied line over.

5/ Adjusted the colour of that line for the shade, repositioned it as a shadow and feathered it.

6/ Paste the copied again and adjusted it's colour for the highlights, then repositioned and feathered that.

7/ Looking at the result, I could see the "shadow line" looked unnatural, so I broke that - shape editor+B and adjusted the positions of both pieces until they fit the curve.

8/ Then I drew a shape for the shadow of the sphere on the line and put a linear transparency on that.

9/ Finally I selected all the line components and clipped them with the base line shape - Q.

[Psaumure]

Thank you for the suggestion. I never thought of using clip-view. In addition, I want to thank you for taking the time to attach a sample for me to take apart. It was very useful. I worked on the sphere for a little bit today. Here is what I accomplished so far.