Your choice of a color palette can happen before any stem is even cut. With this single decision, the rest of the arrangement becomes easier because there are fewer competing choices for the eye to navigate. Instead of buying a flower just because the color in its own little bouquet is pretty, you are selecting flowers that can coexist in the same vase in a design that doesn’t feel loud, dark or off-balance.
With just one beginner floral arrangement, you may find yourself with two main colors and a third, softer color that provides support: blush colors, cream filler and soft greens or yellow focal flowers with a lighter, pale orange filler and greenery. It is not about making a perfect color-wheel arrangement, but about giving the eye a place to go.
The harder it can be to control a color if it shows up in too many places, in too many same-size and same-height flowers. Red, bright red or even deep purple can be a very attractive focal, while another deep purple may look good as a filler, and a hot pink is a great color choice as a line flower, but these can easily compete with each other. If you are going to use a powerful color like this, make a spot for it, use it in one or two focal flowers, and then balance it with some greenery or less saturated colors on the outside.
Texture is also a factor in how color appears, a round bloom will have a more dominant color than a filler in that same color. Glossy foliage will look darker and crisper than matte green foliage and so on. When making a choice of flowers, it makes sense to consider the color of the petals and the buds, as well as the greenery together rather than in individual clumps. A color might look less impressive, but more useful, if it is holding up a more powerful one.
One exercise might be to put all of the flowers out on the table before starting the arrangement and remove any that don’t seem to fit the color scheme. You would use one focal color, either one lighter or darker and either a darker or lighter color as a supporting color, and one or two shades of greenery, or a single color with a supporting greenery color. Using one small vase, start with fewer flowers than you think you need. Add the focal flowers, a few filler flowers, maybe a line flower or two, pause, and think. Is there contrast that is needed? Softness? Some room in there?
One issue new florists can struggle with is deciding on flowers in their favorite colors. Your favorite color matters, but color in an arrangement needs to be considered as much proportion. You may love a color, but a very favorite color will overwhelm a small arrangement if it is present in every direction. Use a stronger color at the point you want to draw attention first, but use the same color more subtly or not at all. Use filler flowers or greenery to tie it together rather than making a new color statement with every stem.
After the initial cut, take a step back and take a quick glance at your floral arrangement. You won’t be able to see the details as clearly and you will be more able to see the main color masses. If you feel a side is much darker, much brighter, or a lot heavier, adjust that stem before adding in any additional flowers. You can have a helpful color combination that is not over-complicated, but one where the focal flowers stand out a bit, the greenery stands out more, and the whole thing is easier to adjust.