The color of preserved plants can fade due to several factors, including:

Exposure to Direct Sunlight: Prolonged exposure to direct sunlight can cause the dyes used in the preservation process to break down, leading to fading.

High Humidity: Excessive humidity can affect the preservation process, causing the dyes to seep out or the plant to lose its color.

Airborne Pollutants: Dust, smoke, or other airborne particles can accumulate on the surface of the plant, causing discoloration over time.

Improper Care: Using harsh cleaning methods, abrasive materials, or placing the plants in areas with fluctuating temperatures or high moisture can contribute to fading.