Yes, you can overdose your roses with chemical fertilizers and pesticides. I would try to avoid doing this again, but if your roses aren't showing symptoms after a week I wouldn't worry.

I have noticed that some roses have paler leaves with green veins. Maybe coincidence or a symptom of fertilizer damage? Also, is it possible for the leaves to go from shiny to matte? Thank you so much for your help!

Fertilizer burn usually causes brown crisping on the edges of the leaves. You are describing chlorosis, which can be caused by a variety of deficiencies (some related to pH) or over-watering. Since you fertilized recently and are using (I assume) commercial potting mix, over-watering might be a problem? How much/how often are you watering? In any case, I'd be hesitant to dose them with fertilizer again until the fertilizer that is in the soil has had some time to leach out. Many commercial potting mixes already have fertilizer in them.
Re: Shiny to matte leaves, new growth may tend to be more matte at first -- perhaps this is what you are seeing. I wouldn't worry about that.

Good to know! I plan on putting them in the ground next week. The rose bed wasn’t ready when the bare roots arrived. When I potted them, I mixed native soil and bark mulch. When I plant them in the beds, how much of composted steer manure should I add in?

There are different schools of thought on how to prepare the ground for roses. If you are amending the soil in the entire bed, then consider layering the manure mixed with soil towards the bottom, and putting a layer of unamended soil above it, so the roots of the roses you are planting won't be directly in contact with the manure. If you amend the planting hole, you could dig it extra deep and wide, and put a couple of shovels full of composted manure at the bottom of the hole, capping it with plain soil so the rose roots don't directly touch it. Alternatively, some people dont' amend their planting holes at all on the grounds that roses with rich planting holes can end up treating the hole like a pot, and not expanding their roots out into the surrounding soil. You do you -- there is no single way to do this successfully. My main message would be: don't put compost directly against the roots of a newly planted rose.