Many succulents will change color in full sun, usually to red. But, IMO, your cacti looks burned - it was growing in very low light - evident by extremely thin and very light green color on the new shoots. So even indirect outdoor light (that is likely more intense than dark indoors) would burn it.

It should not need any support (the ribbon) if healthy, I am not quite sure but maybe there are some problems with roots? Is it wobbly from the base? Did you start watering and maybe fertilizing it more suddenly?

Most of the offshoots look quite good otherwise at this point. It should be much happier outdoors, but first needs to be healthy. The moss on top should be removed asap, and I wonder about soil it is potted in? Is there a drainage hole in the container?

Hi! The dish has a drain hole. I rarely water this guy. He sits on my dining table and I water him maybe an average of once a month? Or even more?

The dish was given to me and included 2 other succulents that died almost instantaneously so I took them out. What was left were these two cacti.

These two cacti that are left are odd

The clump at the back seems to barely be growing. It looks almost the same as when I got it a year ago. But it's still green so I figured it's "okay".

The cacti with a ribbon on the other hand; grew a LOT. It grew arms; it grew offshoots (those circular things at the base), etc. He was just one column a year ago and now he has grown taller and with new arms. He started to lean towards the window at the far end of the dining room so I started rotating the dish. It didn't do anything so I decided to put ribbons to support him and help him stand while (I assume) his roots grow bigger. He is not soft anywhere; firm all the way.. So I don't think he is leaning from rot. I thought he was leaning for more sun, and that's why I moved him outdoors, thinking it would be better for him.

Until the tips turned reddish, and got me concerned.

I put him back indoors now, but beside a NE facing window. I'll see if he gets greener again.

i will remove the moss ASAP. It came with the arrangement so I didn't think it was bad for the plants.

Should I repot?

i believe this dish is using pure garden soil. I have a cacti potting mix I can repot him in. But I was hesitant to do anything because he was growing so fast.. I didn't want him to die if I repot.

im a novice at gardening so I'm very nervous about making any moves with them.

let me know your thoughts on my next step.

Thanks so much! I am SO happy you replied to me post. I have been waiting eagerly for some help!!