Creating a clean gradient in InDesign without the gray
When working in InDesign, one challenge you might come across is how to make a fade from color to black without including a dirty looking gray in the transition.

Unlike Photoshop, when using the gradient tool in InDesign, each color appears to be removed instead of added or combined together. The absence of color midway through the fade results in an ugly gray tone.
The work-around
To avoid this, create the flat color first and then above that object, create a second object, assigning a white to black gradient to that instead.
Right-click on the gradient object and select effects > transparency. Set it as multiply to achieve the desired result.

Pictured is the intended fade from color to black without the gray appearing in the transition.