Today (Oct. 8, 2018), I was able to grow my first field oxide. I had the tube furnace hovering between 1000C and 1050C while I pumped steam into it by a boiling vacuum flask right next to it.
After around 50 mins of heating, I pulled the wafer back out and I saw a yellowish to purple tint; it looks very yellow on camera.
Looking at a chart, it indicates 400 – 490 nm. However, it was my first time and it very well could have been much lower than that.