The color painted on the end coils of a torsion spring identifies the wire diameter. This is the DASMA industry standard color coding system.
White
.177"
4.50 mm
Blue
.192"
4.88 mm
Green
.207"
5.26 mm
Yellow
.218"
5.54 mm
Red
.225"
5.72 mm
Brown
.234"
5.94 mm
Orange
.243"
6.17 mm
Gold
.250"
6.35 mm
Light Blue
.262"
6.65 mm
Tan
.273"
6.93 mm
Black
.283"
7.19 mm
Silver/Gray
.295"
7.49 mm
Purple
.307"
7.80 mm
Copper
.331"
8.41 mm
Red/White Stripe
.362"
9.19 mm