Staubgrau = dusty gray

So is Euro 1 Grey. Same color.

The correct color is RLM 66 dark gray regardless of Revells instructions 

Thanks Blacksheep. I have not seen that site. Thanks for the research.

Doing a bit of research on www.paint4models.com website, I've come up with the following matches to Revell's Dust Grey:

Model Master Euro 1 Gray #4750

Pollyscale Panzer Dark Gray #505110

Gunze RLM Dark Gray 74

Vallejo Gray Green

Life Color #UA072 Grey RLM 74

In short, neither RLM 2 or RLM 66 is the correct color match. Dusty Gray is RLM 74