Round Illustrator path as a start point to create a 3D Sphere. It is very easy to create the design using graphic styles and with the appearance setup. You can always re-apply the effect over and over to a round path (it doesn't work so well with objects that are square or type etc), so you don't have to re-create the effect by hand each and every time (even better is to save the result to the CC library for future use)
Create or select a circle path. Select the gradient tool. Double click the icon in the tools panel or press return or go to the window menu and display the panel and set it to radial type. Draw out the preset on the current selected circle and place the origin point close to the top left of the circle and drag the length out to the edge or beyond of the circle. Go to the panel and set the first stop to a light color such as white etc to create a highlight. Go to the end stop and set it to a dark color. If you want to give some luminance to the edge, you could make the next to last stop the dark stop and make the last stop a lighter one and drag the length of the gradient beyond the circle but position it so you can see a subtle lightness around the edge of the path. Go to the graphic styles panel (window menu) and you can now save this via the right side menu as a new style for future use.
Go to the appearance panel and with the path selected and the fill entry selected, go to the right side menu and select duplicate. You can then change the origin position and lengths of the duplicated item using the gradient as well as go to the panel to tweak the stop color. It used to work fairly smoothly but for some reason with the latest release, it seems to be less flexible but combinations / blends between multiple fills can be achieved to create different highlights using overlay, darken etc. Once you are happy with your combined fill design then you can go to the graphic styles panel and save it.
Once you have your style, you can apply it to other shapes and also the artwork can then be exported either via the file export commands as a PNG etc file or copying and pasting into other parts of the Creative Cloud or by adding it to the libraries panel
You can also combine the result of the gradients and use transformations which are also live effects and can be altered to make spirals, circular artwork and much more. Select the path and go tot he effect menu. and distort and transform. Set the number of copies to 10 or 20 as well as set the scale to 130% and you will fill your entire art board with multiple colorful copies of your path to create a wonderful echo design. Set the scale to 95% and the move horizontal to 20pt and you will see a row of your colorful globes. Set the move horizontal and vertical to angle the row. Set the number of copies to 40 and set the scale to 95% and both moves to 10pt and set the angle to 2 or 3 and you will create a spiral design. The effect is live and you can go back to it at any time via the appearance panel.
Select the the ball shape and duplicate it and position it away from the original and then go to the blend tool and click on both to create a blend. Click on the tool and set to specified steps and set to 20 or so and click OK and you will have a blend between the two (or three etc). You can resize one of them by selecting the entry with the direct selection. You can also recolor one and the entire blend by going to the edit menu and adjust color balance and setting the cyan,m magenta, red etc
You can select the path with the design, you can go to the edit menu and adjust color balance and re-color it using the sliders to change the cyan, magenta etc. You can also recolor by using the recolor artwork feature and color theme picker as well as selecting from a range of libraries including pop art, baroque etc