The garden soil is the Canvas. When its dug over, and organic matter added you have a blank canvas ready for your colours..
The Golden Rudbeckia Is mass planted for a bright yellow border. Planting a single block of colour contrasts to the drifts of the other planting.
If the Soil is the Canvas, and the flowers are the paint applied to the Canvas does this mean that Gardeners are artists?
It is a constantly changing painting, with weather, seasons, weeds, and bugs effecting the natural artwork.
I think they did a good job of the main borders.They looked good even in August.