The smallest hydrangeas are rebloomer mopheads that grow about 2-3' wide (2' if the old growth gets killed by winter) and none is evergreen in Zone 6. Paniculatas tend to be more bloom hardy but they are much wider still. For a 30" wide evergreen (or deciduous) plant, you may want to consider another type of plant.

How about Wee Whitehttps://www.provenwinners.com/plants/hydrangea/invincibelle-wee-white-smooth-hydrangea-hydrangea-arborescens

Then again Little Quickfire https://www.provenwinners.com/plants/hydrangea/little-quick-fire-panicle-hydrangea-hydrangea-paniculata

I do have quick fire in another area and like them very much

Dwarf Hydrangeas that change color would be perfect!!

Bobo is I believe the smallest panicled Hydrangea and gets to about 4’ in all directions. Panicled hydrangea is the only species I would expect to be happy in that much sun.

I would question the wisdom of putting any of the H. arborescens, macrophylla, or serrata cultivars in that particular setting (late morning to afternoon sun in zone 6), especially since it is in a garden that you won’t be monitoring for moisture on a daily basis. All of these species prefer shade during the hottest part of the day and will often look limp in afternoon sun with flowers aging more quickly, even with careful attention to moisture.

New this yr Lava lamp flarehttps://bloomineasyplants.com/plants/lavalamp-flare/

Lavalamp Flare looks like a reasonable choice, Hyed. Plant patent says about 3.5’ tall by just over 2’ wide.

https://patents.google.com/patent/USPP26928P2/en

would definitely need deer resistant

Looking also to move a couple of Hydrangeas to join a couple of quick fire Hydrangeas however the area gets mid morning to late afternoon sun will the displaced Hydrangeas tolerate this type of sun exposure. Not sure which variety they are but they do have big round blooms. Just have to move them because they are buried amongst many evergreens

Deer do eat hydrangeas, unfortunately. If you have deer browsing your garden, you might want to consider a different flowering shrub. Check this out: https://njaes.rutgers.edu/deer-resistant-plants/

went with Bloomstruck Hydrangeas hopefully I will have good luck with these

Bloomstruck will likely grow too big for the space you described above. The Endless Summer website lists 3-4'H x 4-5'W for its mature size. Mine are already at 2.5'Hx3'W after one growing season in the northeast. Maybe deer will keep them trimmed and small :)

If the deer keep them small and compact, they will also keep them from blooming much, if at all :-))

Realizing that I live in a very hydrangea friendly climate, my Bloomstruck is a good 5' across and 3-4' tall......exactly as descibed by the website. And it is ony 2 years old.

Deer here love hydrangeas.....especially the flower buds!!

(listed by Rutgers University as "plants often severely damaged")

Honestly I live in the Northeast and I do spray other flowers in my garden to keep Deer away but have never sprayed my Hydrangeas and have had no problems with Deer touching them

Who knows?! Deer in different areas have different appetites :-) But just be aware that hydrangeas can be a favored menu item.

Saturn, little confused you start off looking for a Small compact hys that will changes color ... we give some great choices for 30” space but you go with a ES( Bloomstruck) that get 4’x5’...plus needs Winter protection, here in the Northeast Macs are Very Iffy

https://www.whiteflowerfarm.com/hydrangea-endless-summer-bloomstruck from what I read