The colour coding is an IDE thing that relates to whether the library is locally embedded or something?? I can’t remember… Google it 
Anyhow, it is irrelevant to it’s general operation, so nothing to worry about.
You need to change how your code fits… use Blynk functions like BLYNK_WRITE() to contain the slider info and the motor commands.
Search this forum for keywords like Car, Rover, Motor, etc. to see how others have done it. Whether WiFi or BT/BLE, the process is the same.
Here is a basic H-bridge controlled rover I made ages ago and converted to Blynk control…
Also, do not not dump all your code in the void loop() as that is not good for the Blynk timing.