Metal roofing conducts heat 200-400x faster than asphalt. That
makes color choice more impactful than on shingles — a black metal
roof in Phoenix or Cottonwood can run 40°F hotter than a white
metal roof under summer sun.
The Solar Reflectance Index (SRI) cheat sheet
SRI ranges from 0 (perfect black) to 100+ (perfect white).
Higher SRI = cooler roof = lower cooling cost.
Major metal manufacturer SRI by color (2026 data sheets)
McElroy Metal — Galvalume Plus paint system:
- Slate Gray: SRI 35
- Sandstone: SRI 41
- Clay: SRI 39
- Cool Bone White: SRI 78
- Cool Solar White: SRI 87
Englert — Series 2000 Kynar 500:
- Charcoal Gray: SRI 28
- Hartford Green: SRI 32
- Cool Buckskin: SRI 49
- Cool Sandstone: SRI 56
- Cool Stone White: SRI 81
MBCI / NCI — Galvalume Plus:
- Patina Green: SRI 38
- Slate: SRI 35
- Cool Light Stone: SRI 62
- Cool White: SRI 84
Tip: "Cool" prefix on a color name signals SRI > 50. These are
the colors that qualify for utility rebates + 25C tax credit.
What color saves you in real dollars
Modeled on a 2,200 sq ft Prescott Valley home with central AC,
summer cooling cost:
| Roof | SRI | Annual cooling | Savings vs charcoal |
|------|-----|---------------|---------------------|
| Charcoal gray (SRI 28) | low | $1,180 | — |
| Slate gray (SRI 35) | mid | $1,120 | $60 |
| Cool buckskin (SRI 49) | mid | $1,030 | $150 |
| Cool stone white (SRI 81) | high | $880 | $300 |
Savings stack with rebates. White Prescott Valley roof = ~$300/yr
cooling savings + ~$220 APS rebate (one-time) + $1,200 25C tax
credit (one-time).
Payback period for cool-color upgrade vs charcoal (typically
~$800-$1,200 premium): 3-5 years.