Does it have to be a shrub? What about some of the gold hostas that are large? Sum and Substance, Sun Power are two of my favorites for large yellows that draw your eye to a space,. Both are old enough to be reasonably priced, or get divisions from a friend.

Perhaps Ogon Spirea? We have them on either side of our driveway entrance, they stay bright yellow green year round. Small white flowers in early spring.

http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=d781

We have them backed with lorapetalum, makes the yellow green seem almost fluorescent sometimes.

Lemon Candy Nine Bark

Ogon Spirea is my FAV shrub! This isn't great pic, but it gives some perspective.

There will be room for hostas have Sum substance

I love Ogon but mine are 6 ft tall. How about S. 'Golden Elf'? About 18" max in height.

many yellow plants need full sun to maintain the yellow thru the season.. else they tend to green up as the season progresses ...

do you have the requisite sun?

ken

Conifers? Picea abies ‘Gold Finch’ or ‘Dandylion’?

I second rouge on Lemon Candy Ninebark. Also, very pleased with Ogon spirea. I have heard Ogon will not get 6' tall up here. Probably doesn't further south. Mine is only 3' tall, but it is still young.

Another option would be a gold mop, but they take a long time to get any size. Pretty and yellow, though!

https://www.gardenlady.com/i-love-gold-mop-cypress/

aralia cordata Sun King

This is one of my fave shade perennials but I am not sure it would work for linnea56 as it can for sure grow taller than 3 feet and unless it got lots of consistent water I dont think it will thrive in a "midday sun" aspect.

I second rouge on Lemon Candy Ninebark

deanna how large it your LC? I ask as I am only able to keep mine at 4 feet because of pruning. And so it might be too tall for linnea56.

Mine is only three feet. I juts purchased it last year, and I prefer purchasing shrubs small so they can grow into their spot. I believe the thing that could potentially keep mine smaller than average is the fact that it is a tasty meal for something (assuming the ninebark beetle) which heavily defoliates it in late summer. Same for my Amber Jubilee. I'm sure that puts somewhat of a halt to its growth. Overall, though, my Lemon Candy is too young for much information.

I'll add that I have placed it at the end of a shady walk, but the shrub itself is in the sun. The effect is that the shrub just glows in the sun, catching your eye while in the shade. I'm very excited for it to grow in the coming years.

'Chardonnay Pearls' deutzia may be a consideration.