Answer: Based on your description I am not certain which type(s) of hibiscus you have. As far as the label, if the cold hardiness tag did not include a USDA winter hardiness zone number (you are in zone 5) then it is very possible they may be tropicals.
There is the tropical hibiscus (Hibiscus rosa-sinensis) which has dark green, glossy leaves. This plant is not winter hardy in your area, and must be brought indoors when temperatures are about 50 degrees. I suspect that the peach flowered plant you have are of this type because the hardy hibiscus do not include that flower color; too, yellow is rare in hardy hibiscus. (The red may also be a tropical.)
There are some winter hardy perennial hibiscus plants, primarily Hibiscus moscheutos and related hybrids. These tend to have flowers in the pink, white or red color range with a paler or medium green leaf that is not glossy. These would be winter hardy in your area with a generous mulch applied in late fall. They die back to the ground and regrow the following year, usually coming up in very late spring when the soil has warmed up.
There are also the hardy shrub hibiscus, Hibiscus syriacus. This is a woody plant that should be hardy for you as long as it is planted in a well drained location. Flowers here are usually white, pink, purplish or occasionally blue.
To help you try to identify your plants, you might try the following web site which shows photos of many of the hardy plants -- please check the winter hardiness rating in the individual listing for each variety.
Here are many photos of tropical hibiscus, to show you the difference in the flower and foliage.
You could also take photos and work with your local professionally trained nurseryman and/or county extension to try to determine which kind(s) of hibiscus you have. I hope this helps.
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