Would Lamium with silvery leaves and either white or 'pink' flowers be an option? I'm guessing you'd want to naturalise the bulbs as the maples sometimes have a lot of near surface feeder roots and wouldn't appreciate the annual ritual of bulb lifting. Smaller bulbs, such as snowdrops, species tulips, and some of the multi-flowered Narcissus could come up in open patches or through the Lamium. Vinca minor would give a deep green cover under the maple and would probably flower. It works pretty well for disguising/distracting from withered brown leaves. Apart from a few 'hang on a see what's for Christmas' Narcissus (such as Earlicheer) most of them have finished by late spring, early summer and are ready for lifting if necessary. (Leaves have browned, dried off, fallen away. Check that your area is not plagued by Narcissus fly. They lay their eggs just where the leaves have left a hole. When they hatch the maggots settle in to the middle of the bulb and feast on next year's flower and leaves. Disheartening - and squishing the little pests is no consolation at all.)

The ability of tulips to perennialize (come back annually) has been sacrificed by excessive hybridization. Species tulips tend to be the most reliable for this perennial trait, although some hybrids (eg. Darwins) will return and rebloom for at least a few years, more so if you provide them with drier summer conditions. Generally, hybrid tulips are treated as annuals and replanted each year. And I'd also suggest investigating the need for prechilling before planting. It's not necessary in my zone 8, but winter conditions can vary widely and southeastern US zone 8's generally recommend prechilling before planting. And I'd consider 6 weeks a minimum - 8 would be better.

If it were me: I'd remove the weed cloth now. I've not seen it do anything good for the development of a good soil structure in clay. Gravel: I'd be thinking a mix of sizes rather than a single screen size. My preference would be for 2,5,7mm which can be useful when it gets dug through the soil/clay. As I'm using it as a mulch I wouldn't put it on any thicker than 2". Less could be better.(Sand is a no-no. It's like uncreamed butter and sugar in an angel cake...). As I'm planting into clay, and if I didn't have too many bulbs, I'd dig out circular shapes for my patches of colour to the depth for my zone and a little extra. Into the extra I'd put a layer of about an inch of the 2mm grit so the roots can get started into a better-drained area. If I could, I'd get a grit that stood out in colour from my soil. Later, when I come to lift the bulbs, I'd be able to see when I've 'hit bedrock' and I'd know to move carefully so I didn't harm my bulbs. Because I'm wanting to improve my soil over time, I'd add some agricultural lime - about an ounce to the square yard. Once I'd covered my bulbs I'd ensure that I stayed off that ground to prevent it from compacting. That's particularly important over times in the year when it's wet. The sad-looking bulbs: I'd plant them up in containers and I'd plant them quite shallowly. Barely covered, and in a free-draining mix - even 50:50 small grit and potting mix with no peat. I wouldn't want the water to stay close to them and I'd want whatever roots they can produce to have lots of encouragement to forage. (I'd even rescue the ones I tossed and give them a go, too.) Those containers I'd put where they get not much more than a couple of degrees of frost, moderate water, and good sunlight. A bit later on, when I see green noses above the soil/gravel (yes they DO come up through gravel) I'd feed them at the prescribed amount with either some potato or tomato food - powdered so it slowly breaks down, and lightly stir it in to the surface of the soil/gravel. Just once. With the damaged bulbs - some might flower. Some will die. Some might only put up leaves and split into smaller bulbs. Which is fine, because I can grow on those daughter bulbs for a year or two to give me 'free bulbs'. Any with streaky leaves I'd dig up and burn because they might have a virus and I'd rather be safe than sorry. All it needs is one travelling aphid and it could spread. No thanks. And next year, when the bulbs are finished for the year, I'd be putting my grass clippings onto the garden strip with a light sprinkling of lime, followed by as many autumn leaves as I could scrounge. Welcome mats for the earthworms. As an aside - if you do use the smaller grit sizes you can plant into it. The small 'johnny-jump-up' pansies, florists' anemones, verbascum, dianthus-pinks, linaria, eschscholzia, and a good range of other annuals will grow there - especially if you can provide some water over the summer. They may not be huge/lush but they will be sturdy and colourful. When it comes to weeding over the gravel (yes you DO have to weed...:-( ) use a two-tine hand fork or weed hook rather than anything conventional. If you use a knife, that will work, too. Forget spades - and rotary tillers. They're often not good for the health of the soil structure on clay.

I do have a white garden a section of the whole garden, if you don't count the coral Lycoris radiata in August nor the pink Crinum that I cannot kill nor the Spring and Fall crocus. It is unlike Vita's in that hers included many grey leaved plants to extend the effect. My leaves are an emphatically green background for the flowers, Taxus media, Vinca minor (white flowered), Nandina (white berried), Daphne odora marginata, Skimmia japonica (white berried), and the various leaves of flowering plants, roses, ('Katharina Ziemet', 'Blanc Double de Coubert', 'Sombreuil', 'Ilse Krohn Superior', 'White Pet', 'Mlle de Sombreuil', and 'White Maman Cochet' - 'Bolero' died but will be replaced in multiples), Helleborus niger, H.xhybridus and bulbs, Tulipa 'Purissima', Narcissus 'Thalia' and Colchicum autumnalis alba. The Gardenias, Citrus trees and Tabernaemontana grandiflora (an unfussy gardenia relative) reside in this patio garden in the summer so I guess that's more white. Cath