You can show the concept
of adaptive camouflage with a relative small sketch.
Place 1 or more colour sensors - https://www.sparkfun.com/products/10904
- under your Arduino (you might need to multiplex).
These detect the colours (+position if more) under the Arduino.
Above the Arduino you let 1 or more RGB LEDs reflect the colour seen by the sensor. (place a paper on top to diffuse the light).
If you now move the Arduino above a coloured landscape the LED's will adjust their light to the ground underneath showing the concept of adaptive camouflage.