Gels to simulate light at sunrise

I have a portrait that I am planning on shooting and need a starting point as

to what gels I should buy to simulate the color of light at sunrise thanks John

John,

The color temperature of the sunlight in the first hour of sunrise is about 3200 to 3500 degrees Kelvin, or just a bit less warm than an a quartz halogen lamp and around photoflood temperature, so using a full CTO gel will bring a daylight source such as flash down to approximately the right place. Real world sunrise and sunset light contains both direct diffused sunlight at the horizon and skylight from above. The skylight is very noticeably bluer than the direct sunlight, so the light is actually a combination of very warm light and rather blue light. That blue skylight can be several 1000 degrees Kelvin above 5500 degree daylight sources. To get the most accurate simulation, you may want to use two different sources at different color temperatures.