Paleotemp,
It was located in very bright area with one hour of filtered morning sun and about 30 minutes of evening sun. I agree sun exposure makes a difference along with soil moisture level. Sun is very intense here during summer months, so I do not want to put too much stress at this time but I will next time around. We are also experiencing high morning temperatures. I have found out that cool mornings add more color. I have been observing semps almost everyday. I noticed that some semps had red hues on tip of the leaves when morning temperatures dipped down to lower 60s during late May. Unfortunately that has only lasted 3 days so Red hues disappeared when morning temperatures went up again.
Daniel, I had " Black" first year of my acquaintance with semps. I got it from local nursery so it did not have much color when I got it. Unfortunately they only last a few months before they disappeared. I am learning little more about them every year so I will hopefully get some variety that will last until flowering stage.