Some flower pigments just don't last no matter what you do. I had some lovely California poppies that faded from orange to cream as they dried

If having them be both natural and colorful is critical, check books on drying them to see which ones are listed as keeping their color.

Painting them after you make the arranfement is also an option.

I do most of my work framed, under glass and keep them from direct light as much as possible.

Have you considered dried autumn leaves. They see to retain the colors well. I made a simple wreath out of a piece of cardboard and pasted on the leaves. It was really pretty. Next year, I am taking this craft idea to an old age home for an senior activity.

I make press-leaf collages. While the drying process leeches color from leaves and flowers, I don't experience much color loss after the works are framed. I don't yet use any preservatives, but I do leave the leaves and/or flowers under pressure in a dark & dry place for about a month or longer. I read somewhere that this helps to preserve color; so far it works for me.

Recently I read an article about a florist sealing floral elements with polycarbon and mounting them on dehydratng board to stabilze the color. I haven't tried it yet, but it's worth considering.

I recently made some lovely dried fern pictures and knowing they would fade, sprayed them first with a light spray of florist paint. My daughter makes beautiful wreaths of dried flowers, and she always sprays them first. They last twice as long. I'm sure you all know that they should never be exposed to the sun.

I glue fresh flowers and leaves between two sheets of tissue paper. The petals are fresh when they go on and dry naturally as the paper dries. I also iron the paper to help preserve the petals. After a time as the flowers dry, the lovely colour fades. The flowers do need to be wet as they go on otherwise they do not apply well. Does anyone know of a preservative that I could use to soak the flowers in before applying them to the paper, so that the colour is preserved? Any suggestions gladly received.
Thank you.

You could try Krylon uv resistant spray for color retention.

my flowers are getting eaten even though there is bug killer on them HOW?

i've asked this question 3 times and no answer

There are several things you can do to help preserve colors. First, pick and press flowers on the first day they are fully opened. Make sure they are completely dry. Using a microwave press then finish drying between sheets of desiccant paper helps. When completely dry, you can color enhance with pan pastels and/or copic markers. Ferns and other greenery can be sprayed with Design Master floral spray - basil is a good color choice. Darker color flowers last longer than light colors for the most part. Finally, framing using anti UV glass or acrylic makes a difference. Hope this helps!

My experience tells me if there is only the slightest bit of moisture on the flowers, they will turn beige or brown. I like to pick them around mid day.