Is it possible to color titanium in an oven (to control the temperature)? If so, what temperature does the oven have to have?
Assuming a kitchen oven, the answer is, No.
If you have a laboratory oven, a kiln, or some such, then the answer is, “Probably”.
Titanium colors by heat are controlled by temperature much like anodized color is controlled by voltage. The temperature at which you should start seeing the lowest tan/bronze is about 640°F. This is easy to reach with a direct flame, but not in a household oven.
I have not found a color/temperature scale, but would love to publish one. If anyone with a lab oven wants to play with this, please share your results.