There might be different runs DE did depending on the year. Take a look at these stickers on an R&B machine. They seem to be a different color, and the "Install 3 Balls" one is completely different:

https://www.flickr.com/photos/37999418@N04/6925333622/in/set-72157629437568588/

Here's the original caution sticker in my R&B backbox (apologies for the condition and curled edge on the left). It was secured to the panel with staples, which you can see have rusted from 20 years of public use in the humid south. The background color is again that yellow-green hue as seen in RussMeyer's R&B machine stickers in that link I posted.

DE-R&B-Panel Caution.jpg

In that yellow-green hue or just the orange in your OP?

A little lighter on the color. Like have the blue value at 100. Here's one of the ones I did last year for my machine:

R&B Pinball Scans - 201 - 2-Way Level Notice Sticker.png

The install balls sticker is white and narrow on Russ's machine. Here's a blowup of it:

russ3balls.jpg

I found pictures from an auction of a factory mint R&B machine. Looks like it originally used the red-inked "INSTALL 3 BALLS" sticker:

r&b lockdown.jpg