In a simple test here, I didn't get a crash with the latest daily in either approach, but if one crashes for you, you might try the other
- Single CoronaMtl, with C4D native Layer shader in the Diffuse, with two colors set as layers and a Noise as a Layer set to Layer Mask mode.
- A CoronaLayer material, with two separate CoronaMtls inside it so that each has a separate Diffuse channel with the color set as needed, and the Noise used as a Mask for the non-base layer
The first approach would be preferred of course, as quicker and simpler to evaluate one Material than two, but if one approach is causing crashes at the moment, you could try the other and see if that lets you work around it for now.