Comparison

Mysterious vs Sea Serpent

Benjamin Moore AF-565 and Sherwin-Williams SW 7615, ΔE 2.79 apart

Benjamin Moore Mysterious AF-565 on a wall, hex #454B54
Mysterious Benjamin Moore AF-565
Sherwin-Williams Sea Serpent SW 7615 on a wall, hex #3E4B54
Sea Serpent Sherwin-Williams SW 7615
Zeytin’s verdict · ΔE 2.79Close cousins. Paint a sample of each before you choose.

Benjamin Moore Mysterious (AF-565) and Sherwin-Williams Sea Serpent (SW 7615) measure a delta-E of 2.79 apart. Mysterious is 2.1 LRV points lighter, which is the difference you notice first. Both carry a similar amount of color, at chroma 6.2 and 7.6. The undertones part company: Mysterious reads as a blue cast at hue angle 267.8 degrees, Sea Serpent as a blue undertone at 248.2. Close, but a large sample of each will show the gap, particularly against white trim. If you need the Sea Serpent depth in Benjamin Moore's line, start from its LRV of 6.7 rather than matching by name.

Is Benjamin Moore Mysterious the same color as Sherwin-Williams Sea Serpent?

Not quite, but close - Benjamin Moore Mysterious and Sherwin-Williams Sea Serpent are delta-E 2.79 apart, close enough that most rooms would not show the difference.

What is the delta-E between Benjamin Moore Mysterious and Sherwin-Williams Sea Serpent?

The measured color distance between Benjamin Moore Mysterious and Sherwin-Williams Sea Serpent is delta-E 2.79.

Which is lighter, Benjamin Moore Mysterious or Sherwin-Williams Sea Serpent?

Benjamin Moore Mysterious is lighter than Sherwin-Williams Sea Serpent by 2.1 points of light reflectance (LRV).

CLOSEST PAIRΔE 2.79 Mysterious and Sea Serpent
LIGHTESTMysterious LRV 8.8
DARKESTSea Serpent LRV 6.7
SPREAD2.1LRV points

Side by side

measured values
Mysterious Sea Serpent
Brand Benjamin Moore Sherwin-Williams
Code AF-565 SW 7615
Hex #454B54 #3E4B54
Light reflectance 8.8 6.7
Undertone blue cast blue undertone
Chroma 6.2 7.6
Hue angle 267.8° 248.2°
Color family black black

Each on its own

full detail