I have tried some possibilities but it seems, there is a obstacle you can not solve.
To insert the M-Code M25 on a certain place is easy to do when you have a clear defined goal such as " layer 1 ".
But you insert a command and commands must be conform to the conventions.
M25 " .... " is not conform and
M25; "change to Red" is after the semicolon a text, but this text will not be readed to execute.
The M25 command interupts the print and I have no informations found, that it also can write a text to the display
There is surely existing another command to display textes but I dont know any one.
M25 stops all following commands just to the resume signal.
Inserting an additional command below the M25 will not be execute when pausing. Inserting an additional command above M25 must hold the text on the display as long as M25 stops all other commands