Extra day in Eastern France. Where to spend it?

Colmar is a great place to spend any xtra time. Relax enjoy its ambiance.
,take in a museum , colmar is really lovely . It is a favorite of m8ne.

I'm confused about how you plan to handle Beaune. You mentioned seeing it while in Lyon, but it's much, much closer to Dijon.

I enjoyed all of your base cities and think an extra day would be worthwhile in any of them. I see that the fastest of the three routes recommended by ViaMichelin for your Colmar-Dijon leg takes you a bit south of Dijon. I think you could visit Beaune on the way to Dijon if you are comfortable parking your car with your luggage inside it. (I don't rent cars in Europe, so this is not something I've ever had to deal with.)

If you are based in Dijon, why not take the train to Mulhouse? Only about 1h15 minutes.

If you are based in Dijon, why not take the train to Mulhouse? Only about 1h15 minutes, by TGV.

I agree with acraven concerning Beaune which is only 45km South of Dijon. I don't know if you'll be travelling by car but you may also take a train (30min) to Beaune from Dijon. And if you want to get the flavor of Dijon which has a lot to offer, you should add a night as you also want to see Semur and Chateauneuf. You will scratch the surface only!

Check the TO videos:

https://www.youtube.com/watch?v=w5CojSGoJ4k

https://www.youtube.com/watch?v=2AhaK1TFbS8&t=9s

https://www.youtube.com/watch?v=zih7Xss12XE

Perouges, near Lyon, is a picturesque town you will probably like.

There is a famous church in Vezelay, not far from Semur, also: http://whc.unesco.org/en/list/84

I liked visiting the battle of Alesia sight, but history is a highlight for me and you didn't mention that as one of your likes.

I'm not sure about Mulhouse, it's one of the uglier towns I visited in France.

I think it very easy to allow an extra day in any of the three places you mentioned. Are you driving?

Sorry, I always leave out important information when writing the questions. We will have a car, we also love history and we were going to see Beaune on our drive from Dijon to Lyon.

Thank you so much for your replies so far

If you like automobiles Mulhouse has one of the great Bugatti collections in the world.
Mike

Have you thought about going to Verdun? The site of WWI, there’s a lot of history there as well.

With only one day unspoken for, do not add additional destinations.

My impulse would be to add to Lyon--a wonderful place that pushes many of your buttons that you won't get to parse in the single day you have planned to be there.

I'd also recommend staying in Beaune (not Dijon) and taking day trips--a much nicer base than Dijon for a short stay. (I take that back if you have particular reasons for seeing as much of Dijon as you can. It's an interesting city, just not a good base for touring about.)