First thing to acknowledge is that mother nature may or may not provide your particular shade of color. Your florist can only do so much matching. Every flower does not grow in every color. If matching is very important to you, provide your florist with a color swatches of dress fabrics or at least bring paint chips. It is next to impossible to exactly match a swatch with a flower but we can get close. You will be limited in flower choices if you need a particular shade. Your best chance at a close match will be with roses,gerbera daisies and alstromeria. Try not to get consumed with an exact match. Let your florist guide you to complimentary colors and light and darker shades of your colors. If you send your bridesmaids out with coral dresses and matching coral flowers you lose color interest and the flowers when photographed will just blend in - instead go for shades and textures that create interest. If your bridesmaids are wearing a print or pattern it's best to choose one of the colors in the pattern and go with a single type of flower and a few accents . Start trying to mix every color in the pattern and it becomes very busy. There are many ways to mix, match and compliment bouquets, trust your florist. Understand that not every flower seen in a garden magazine is available for retail florists. In our area we get many requests for mountain wildflowers. Very few true wildflowers are grown commercially, But we can easily achieve the same look with flowers grown for cutting. Daisies,sunflowers, delphiniums,larkspurs, and iris are available year round. Wildflowers are spectacular when viewed in their environment but if you look closely they are usually too rough looking to use in bouquets, insect infested and when cut they do not hold up well at all. Plus picking buckets of wildflowers is not allowed in some areas and can be illegal. If your wedding is in high summer there are many times "backyard" field crops grown for commercial use, but again, you will be limited on how much of any one flower you can get.
Never,ever use "dyed" flowers! If your florist says oh we can dye those,please say NO! Never do this for a wedding! That dye can bleed through the stems and permanently stain hands and fabrics! We do, however, have a spray tint that is made for flowers and if carefully used you cannot tell a flower has been tinted. Keep in mind it is a "tint" not a full color paint so you can't go too dark or it will look fake. It is safe to use on some flowers but not all so again, always trust your florist.
Up next, corsages and boutonnieres