Simulation mode in CoDeSys
the simulation of the program allows you to test numerous features.
With the simulation active, you have to log in - but it seems from the image that you did it, as well as then switch to RUN-
To force the contact, once you have positioned the mouse over the one you want to try, double-click, until a blue square appears, then press F7 which indicates the forcing command. If you have no other points in the conflicting program, your FAN1 output should activate, with a dark blue square inside.
This image is an example, double click on E02 input:
And this is the results, after F7 activation of force command:
Hope this help you
Source: Codesys Manual
Just check the command for activating the second page is true.
You have 2 programs made in your project; PLC_PRG is the main program and others are subprograms and subprograms will be scanned only when it is called from the main program(PLC_PRG).
Just check whether you have called the other program from your main program. I am sure that once you didn't make the logic to call that program or its condition is false.
That's why it is not in blue color. Please check the calling function
Hope this helps you