Preserving Fall Leaves - Keeping the Color ~ Soak leaves in 1 part glycerin to 2 parts water for one full day; lay out to dry.  **UPDATE: Tried this, did *not* work.  Leaves do stay flexible but are somewhat sticky &amp; deteriorated after a while. Have not found ANY method that truly preserves their color if they&#x27;re exposed to any light at all.  #DIY