Cosmo Embroidery Floss

663

Blues family

Cosmo 663 is a medium, moderately saturated blue shade with hex code #646FAF and RGB values 100, 111, 175. Below you'll find the closest Valdani, Crescent Colours, and DMC equivalents — ranked by visual color similarity — plus 8 similar Cosmo shades and color harmony pairings.

Hex
#646FAF
RGB
100, 111, 175
HSL
231°, 32%, 54%
Lab
48.5, 12.8, -35.4
Lightness
54%
Medium
Saturation
32%
Muted
Hue
231°
Family
Blues

Brand Equivalents for Cosmo 663

Top 5 closest matches in each brand, ranked by visual color similarity. How matching works

Cosmo 663

Sullivans

Blue Violet Medium 45070 85% Good
Cornflower Blue Medium 45204 79% Approx
Grey Blue Medium 45475 78% Approx
Blue Violet Medium Dark 45470 78% Approx
Lavender Blue Medium 45437 74% Approx

Crescent Colours

Blueberry Tart 033 78% Approx
Vintage Violet 045 72% Approx
Cool Azul 079 64% Fair
Blue Beatrice 132 55% Fair
Betty Bluebell 048 48% Fair

Similar Cosmo Colors to 663

Closest Cosmo threads by perceptual color distance, sorted from most to least similar.

Cosmo 663
Cosmo 525 Very close ΔE 4.96 Cosmo 165A Close ΔE 5.07 Cosmo 214 Close ΔE 5.14 Cosmo 173 Noticeable ΔE 5.83 Cosmo 526 Noticeable ΔE 5.87 Cosmo 554 Noticeable ΔE 7.71 Cosmo 174 Noticeable ΔE 7.79 Cosmo 2027 Noticeable ΔE 8.06

Working with Cosmo 663

On white fabric
4.7:1
On dark fabric
4.4:1
Temperature
cool
Closest to
violet

It stands out clearly on both white and dark fabric, so it is an easy, versatile choice for any ground.

Color Harmonies for Cosmo 663

Cosmo threads that pair well with 663, based on color theory harmony rules in CIELAB color space.

Complementary
Opposite on the color wheel — maximum contrast
663
674 Cosmo 674
Analogous
Adjacent hues — smooth, natural transitions
663
2262 Cosmo 2262 2253 Cosmo 2253
Triadic
Evenly spaced at 120° — vibrant and balanced
663
425 Cosmo 425 845 Cosmo 845
Monochromatic
Same hue, different lightness — great for shading
663
216 Cosmo 216 662 Cosmo 662 522 Cosmo 522

Blues Family

Cosmo 663 in context with nearby shades from the blues color family.

663 663 663 2662 2662 2662 164 164 164 173 173 173 2018 2018 2018 413 413 413 2023 2023 2023 525 525 525 253 253 253 174 174 174 214 214 214

About Cosmo 663

Meet Cosmo 663 — a moderately saturated, medium hand-dyed thread in the blues family with true blue tones. Its steady and rich presence shines in skies and water alike. Pull this thread for denim textures or cool-toned backgrounds when you need a dependable shade.

Frequently Asked Questions

Cosmo 663 — what color is it?

Cosmo 663 is a medium blue thread (hex #646FAF, RGB 100, 111, 175). It shows up most in bluebird motifs and whale designs.

What is the DMC equivalent of Cosmo 663?

The closest DMC match for Cosmo 663 is DMC 3839 (Lavender Blue medium) with a 88% match based on visual color similarity. Other near matches include DMC 160 (Grey Blue medium, 77%) and DMC 156 (Blue Violet medium light, 73%).

Which Cosmo threads are close to 663?

The closest Cosmo threads to 663 are 525 (ΔE 4.96), 165A (ΔE 5.07), and 214 (ΔE 5.14). These are useful substitutes when 663 is unavailable or for building gradients.

What is Cosmo 663 good for?

Cosmo 663 is commonly used in cross-stitch projects featuring bluebird motifs, whale designs, sapphire accents, porcelain patterns. Its medium tone works well for standalone motifs and as part of larger palettes. This page includes color harmonies and similar shades to pair with 663.

What fabric color works best with Cosmo 663?

It stands out clearly on both white and dark fabric, so it is an easy, versatile choice for any ground. For reference, 663 has a contrast ratio of about 4.7:1 on white fabric and 4.4:1 on black. As a cool shade, its cool cast recedes visually — useful for backgrounds, shadows, water and sky, and calm, restful palettes.

Cosmo Color Chart Cosmo ↔ DMC Conversion