The ‘noise’ is actually in the print, the blue layer is terribly grainy, and that is true for film generally, the blue layer has the most noise.
In this case, I also haven’t set the black levels, so they may be too high in the blue layer, causing you issues, the black levels should be set so that the base noise level is obscured.

Just on film grain, many people incorrectly think it is the grains are the ‘pixels’ that form the colour information. In reality the ‘fundamental particles’ that hold the colour information are the silver particles and colour dye clouds. The grain is an order of magnitude larger than these particles and is effectively laid over the image, obscuring it with noise, it is not the source of the image itself.