No Rest for the Wicked is the first heist you can do in Payday 3. Whether you want to stealth the heist or go in shooting things up, you are going to run into some obstructions you'll need to take care of before getting into the vault, including turning off the power. I'll tell you below how to choose the correct switch so you can get through this mission flawlessly.
How to turn off power in No Rest for the Wicked in Payday 3
Once you've made your way inside the bank and got to the step where you need to switch off the power to unlock the security gate, head to the first floor, down from the bank stairwell, and to the right. At the end of the hallway, you'll find the IT room, which has the power switch.
Upon looking at the switch, you'll see a green, blue, white, or red switch to turn off. To find the correct one, you need to head back upstairs to find the power room, where you will see a generator with a screen. The screen will display the word Connected Cable, with the color showing up right next to it.
Now that you know which color is the correct one, you can head back down and turn the power off, so you can enter the security gates. Keep in mind: you will need a red keycard to enter through the doors, which you'll find hanging on the belt of guards throughout the bank.
For more on Payday 3, be sure to check out How to link your Steam to your Nebula account in Payday 3 here on Pro Game Guides.