I took a picture of a photograph of two of my friends and me under each of my three color tones of F15T8 Philips Alto lamps. I am in the middle with the plaid flannel shirt :)
Top: Daylight Deluxe (6500K and 73 CRI) This definitely looks the most natural of the three. Our skin tones look the most realistic in this condition and the red in my friend's sweatshirt on the left looks plenty vibrant. The contrast in the plaid in my shirt looks great. The Daylight Deluxe seems to make skin tones look the most natural, and make reds stand out. This light appears to be the most natural of the three, though a little more blue than actual daylight and with an imperfect CRI.
Middle: Cool White (4100K and 62 CRI) The somewhat low CRI makes our brightly colored shirts appear a little washed out. My skin, being fairer than my buddy on the left looks especially pale. I look a tiny bit greenish/seasick in this condition. The contrast between red and other colors is a bit lower. Lower CRI values definitely compromise appearance of bright colors and skin tones. This light seems a little gloomy, like daylight on a cloudy day. This would be suitable for reading and paperwork in an office, but definitely not for an artist studio or a relaxing living room.
Bottom: Soft White (3000K and 85 CRI) Probably my favorite of the three conditions. The excellent 85 CRI and warm color temperature combine to make our skin tones look peachy and healthy, and make the reds in our clothes extremely vibrant. The contrast in my plaid is quite good, too. This light is very much like the wonderful, warm glow of incandescent light.
In conclusion, my favorite is the soft white condition because of the excellent CRI and nice appearance of skin tones. Daylight comes in second with natural looking skin tones and very nice contrast between red and other colors. The cool white is really nice for reading and creating a stimulating office environment, though it can compromise photo appearance due to the lower CRI.