JP
As you probably already know, dark colors (black) will heat up more than light colors (white). Try using thermometer strips sold at pet stores (to stick on the insides of reptile cages to monitor temperature). They're cheap, don't break, are flat so you can put them under a piece of paper (if that's what material you're using) to check your temperatures. Try some materials with different reflective surfaces too (foil; shiny black vs. rough-surfaced black for example).

Willard
I would follow Ben Franklin's observations, put different colors on a block of ice (he used snow). Set the ice in the sun and observe how the darker colors melt down into the ice faster (presuming it will, I've not tried this). another idea might be to set a thermometer under pieces of cloth that are set in the sun or under a lamp to measure different temperatures. let us know how it turns out

Mac
Yes, it can. A number of variables can enter into the picture, so if you conducted an experiment, you'd need to proceed carefully, to avoid skewed results. Emissivity would probably be the key differentiator in your question. (Look up emissivity in the dictionary).

Given two identical glass containers - one being of one color A and another being of another color B and that they would be filled with, say, some identical heated liquid, and then allowed to cool -

And given that the emissivity of container colored A and the emissivity of container colored B is substantially different, then the rates of cooling would be different. [You would need to measure or otherwise determine what the 'emissivity' of each specifically colored glass is.]

Emissivity of materials is of signficant concern in some industries - for instance - if you are building a spaceship - and you want to keep parts of the spaceship cool or other parts warmer. The 'color' (more precisely, the emissivity) of the surface of the ship will determine whether that portion of the spaceship will be cold, cool, warm, or hot.

There are lists that give the values of emissivity of various materials - in books on spacecraft design, thermal properties handbooks, and similar texts.

Two of the main attributes you would want to look at in an experiment that would demonstrate this would be 1. the material's emissivity and 2. the material's thermal conductivity.

To remove multiple external variables from your experiment - you might want to place both of the glasses of liquid into a black box (keeping them out of sunlight/away from external heat / light sources). Don't put them in the microwave either! :-)

And if do perform an experiment - if you use two thermometers or thermocouples, be sure they are calibrated. And gosh - publish your findings here if you do perform the experiment.

If you paint one glass Black and the other glass White, which container do you think will cool faster? Any hunch?,

Anonymous
White reflects more energy than black does. Absorbed energy is of course not destroyed but usually converted to heat so the answer to your question is yes, makes a difference.

The cups would take heat energy from the coffee at same rate, given same material of cup, as this is conductive heat transfer, while the white cup will radiate heat to surrounding air more slowly than the black cup, and so in total the black cup of coffee will cool down quicker.....