Also, but this is of less consequence, Sascha uses the Factor Ouput of the second Noise Texture for both Color Ramps:

So, (and you don’t need to know this) the difference here is, that the Factor of the Noise Texture is just the Red Channel of that Noise Texture.
When you connect the Color Output to a Color Ramp, Blender converts the Color to a scalar Value by taking the Luminance (0.2126 R + 0.7152 G + 0.0722 B) of that Color.