Comparison

Quarry Rock vs Gunmetal Gray

Benjamin Moore 1568 and PPG 1033-6, ΔE 2.11 apart

Benjamin Moore Quarry Rock 1568 on a wall, hex #616964
Quarry Rock Benjamin Moore 1568
PPG Gunmetal Gray 1033-6 on a wall, hex #646C64
Gunmetal Gray PPG 1033-6
Zeytin’s verdict · ΔE 2.11Close cousins. Paint a sample of each before you choose.

Benjamin Moore Quarry Rock (1568) and PPG Gunmetal Gray (1033-6) measure a delta-E of 2.11 apart. They sit within 0.7 LRV points of each other, so neither will look brighter than the other on the same wall. Both carry a similar amount of color, at chroma 4.5 and 5.8. The undertones part company: Quarry Rock reads as a green cast at hue angle 157.0 degrees, Gunmetal Gray as a yellow-green cast at 144.1. Close, but a large sample of each will show the gap, particularly against white trim. If you need the Gunmetal Gray depth in Benjamin Moore's line, start from its LRV of 14.0 rather than matching by name.

Is Benjamin Moore Quarry Rock the same color as PPG Gunmetal Gray?

Not quite, but close - Benjamin Moore Quarry Rock and PPG Gunmetal Gray are delta-E 2.11 apart, close enough that most rooms would not show the difference.

What is the delta-E between Benjamin Moore Quarry Rock and PPG Gunmetal Gray?

The measured color distance between Benjamin Moore Quarry Rock and PPG Gunmetal Gray is delta-E 2.11.

CLOSEST PAIRΔE 2.11 Quarry Rock and Gunmetal Gray
LIGHTESTQuarry Rock LRV 14.7
DARKESTGunmetal Gray LRV 14.0
SPREAD0.7LRV points

Side by side

measured values
Quarry Rock Gunmetal Gray
Brand Benjamin Moore PPG
Code 1568 1033-6
Hex #616964 #646C64
Light reflectance 14.7 14.0
Undertone green cast yellow-green cast
Chroma 4.5 5.8
Hue angle 157.0° 144.1°
Color family gray gray

Each on its own

full detail