Spray paint is no way to get good autumn foliar color in the garden. The healthy rich green redwood trees out in my front garden would look ridiculous and be very embarrassed, not to mention unable to breath, if they were painted yellow, orange and red, like the sweetgum trees that will soon be getting so colorful. Evergreens are meant to be green, and should stay that way!
Just like every other feature in the garden, autumn foliar color takes proper planning. Most of the plants with the most impressive autumn color happen to be substantial trees, so are not as easy to accommodate in as many situations as flowering annuals are. There are a few smaller shrubby plants and perennials that provide autumn foliar color, but almost all are deciduous, so defoliate to leave bare branches through winter.
Boston ivy (which is not really ivy) is probably the most colorful of climbing vines. It is a bit too aggressive for small spaces though, and damages painted surfaces and just about anything that it gets a hold of. It is best on concrete and cinder block walls. Grapevine and wisteria are only moderately colorful.
Currant, crape myrtle, pomegranate, smoke tree and redbud are a few of the shrubby plants that provide good color in autumn. Crape myrtle and Eastern redbud are actually more commonly small trees. Many of the Japanese maples with good autumn color are small trees that stay smaller, rather than large shrubbery.
Here where winters are mild, sweetgum, Chinese pistache, flowering pear and maidenhair tree are the best trees for autumn color, though maidenhair tree turns only bright yellow without the oranges and reds that the others get. Where well exposed, (and only for those who like the abundant squishy fruit,) Japanese persimmon is comparable to Chinese pistache, and stays colorful even longer by holding bright reddish orange fruit late into winter after the foliage is gone. Fruiting pear, apple, apricot, plum, prune and almond trees are not quite as colorful.
Several of the North American and European maples are remarkably colorful, but do not hold their foliage as long as sweetgum does. Silver maple and box elder (maple) happen to be less colorful than the other maples, and can actually be rather unimpressive. Conversely, when autumn starts out with a quick and unusually cool spell, various poplars and locusts, as well as tulip tree and black walnut can almost get as bright yellow as maidenhair tree does.
Tree of the month: Bigleaf Maple
From here north to Vancouver Island, and also in isolated colonies as far south as San Diego, the bigleaf maple, Acer macrophyllum, is the most prominent native maple on the west coast. The box elder (which is actually a maple) is certainly more common in many areas, but does not command attention like the distinguished and bold bigleaf maple does. The vine maple to the north of Mendocino County is a delightful small shrubby tree that provides fiery autumn color, and is more compatible to compact home gardens, but is just too diminutive to compare.
Both the leaves and the attitude are disproportionately big for bigleaf maple. Mature trees are generally only about forty feet tall and broad, unless they need to get taller to compete in a forest. Yet, leaves are about half a foot wide, and can get twice as wide in cooler climates. Because their roots can be somewhat aggressive, and their shade can be a bit too dark, bigleaf maples are best for larger gardens and parks.
Autumn foliar color is typically rich yellow in the wild. More exposed urban trees can get a bit more golden yellow, perhaps with a bit of paper bag brown mixed in. Leaves eventually fall cleanly and efficiently (within a short time) with rain or colder weather, but are so substantial that they can damage ground cover and lawn if not soon raked.