Peter Mohylsky, www.athome30a darker roofs look better than lighter ones. The lighter roofs look old quicker. For energy efficiency, lighter is better, but also the grade of the shingles could make a difference.

there's actual data on this, buried under a lot of "cool roofs are better, probably."

cool roof rating council measures reflectance — dark asphalt shingles run 5-15%. energy star rated white roofs: 65%+. DOE studies in hot climates show roughly 10-15% reduction in cooling costs.

florida is firmly in the "lighter roof wins" camp. whether for you or your friend.

the asterisk worth knowing: insulation and attic ventilation usually matter more than roof color alone. a dark roof with a good radiant barrier and ventilated attic can outperform a white roof on a poorly sealed house. so it's real, but it's not the only lever.

chatgpt answered it.... NOT ENOUGH TO MATTER, but here's what they said.

For a 2,000 sq ft house in Georgia, changing from a dark roof to a light or “cool” roof would usually save about $25 to $90 per year on cooling, with around $40 to $70 per year being a reasonable middle-of-the-road estimate. In especially sunny, poorly shaded, or less-insulated homes, it can get close to $100 per year.

That estimate comes from Georgia-specific electricity use and national cool-roof guidance:

• In Georgia, households that use air conditioning average about 3,019 kWh/year for air conditioning.
• Georgia households use about 22% of total household electricity for air conditioning.
• DOE says a cool-colored roof can cut cooling costs by about 5% to 20%, especially in warm climates.
• Using Georgia’s recent residential electricity price of about 14.46¢/kWh, that puts average annual AC cost near $437/year, and 5%–20% of that is about $22 to $87/year.

A second DOE source says a cool-colored roof on a home can yield annual savings of up to $0.05 per square foot. On a 2,000 sq ft home, that is up to about $100/year, which lines up pretty well with the estimate above.

A few things can push your savings higher or lower:

• Higher savings: full sun, dark old roof, older attic insulation, low shade, second story gets hot
• Lower savings: lots of tree cover, excellent attic insulation, light roof already, well-vented attic

The important practical point is this: for most Georgia homes, a lighter roof helps, but it usually does not create huge utility-bill drops by itself. The bigger payoff often comes when roof color is combined with good attic insulation and ventilation. 

Peter Mohylsky, www.athome30a I would guess location has a lot to do with it. Up North here black may be more efficient and down South light-colored shingles would be more energy efficient. Just guessing.

In Manhattan most of our roofs are flat roof style (also more prone to leaking- but everyone wants roof decks). When speaking to contractors/engineers- most have suggested using lighter color membranes as it will be easier to cool the higher floor apartments in the summer. I wish I had something more scientific to add- but that's all I got. 

Peter Mohylsky, www.athome30a & his dear friend

I got direct, maximum sun on a grey composition roof that heated the home even with a roof fan, roof vent, attic insulation in rafters plus blown-in, & A/C. On the 98-105 degree days, the combo netted indoor temps at 80-84 degrees cool but no cigar. I started closing drapes & gained 3 more degrees of relief. It would not matter (to me) if roof was white or black as direct sun had the final say. In the end, house location & preventative measures rule the day Peter. BTW, they had heat resistant roofing & paint too but expensive. A metal roof would have created a giant pizza oven. A clay tile (too expensive) would have been the best option methinks

Looks like AI may have nailed the answer, Peter. 

Quality insulation seems more important than roof color.

Lighter in warmer climates 

Darker in colder areas.

Roof insulation is key. I have seen homes in Florida with sprayed insulation ( more expensive than traditional forms) maintain 72 degrees during a hot streak with daily temps in the 90's. The roof was a bit darker than the homes around it. 

Seems a combination of insulation and ventilation also pay a big role. 

I am sure that there have been many studies on heat absorption by various colors.

here is Gemini's summary on this.

Don Baker posted the answer from Chat GPT.

You should also take a look at the answer from Grok AI.   I cut and pasted your question and received lots of good info and food for thought.

I have not seen any data on it nor have I looked for those stats. I would assume it would also depend where you lived as well. 

I went to the science museum in Phoenix and they had an exhibit on car paints and roof tiles under a 100 degree heat lamp. White was the coolest to the touch and black and red roof tiles were the hottest. Same with car paint.

Such interesting and informed responses, "scientific" beyond the intuitive. Thank you all! Good question, Peter. We learned so much beyond the obvious.