Sky color problems in autumn

Hello, I have recently bought the Ap weather pack and the west Highland line South. I followed the instructions of how to apply the sky textures (TimeOfDay) of the Weather EP on the WHL, but it didn't work. I then tried it with the TimeOfDay files from the Liverpool Manchester route (whose autumn sky is blue), but it is still grayed out and looks like there is fog all over the place. I have provided a screenshot where you can see that the autumn sky is completely gray, even though I have selected the APEP Clear weather and have replaced the autumn TimeOfDay with the one from Liverpool Manchester which has a clear, blue autumn sky. So my question is, how do I change the sky color/texture to blue? AP couldn't help as the TimeOfDay replacement is on a no support base. Thanks in advance for your replies. (Btw, German replies are welcome as I'm German).