Color Astronomy:

Here is an alternative method for Dr. Elizabeth Roettger's (She gets so exasperated when I call her doctor.) wildly popular Color Astronomy Lab. Here are some web images to look at through the color filters Dr. ER describes in her lesson and some questions you and your students can ponder.
 

Visible Spectrum	Helix Nebula	Cat's Eye Nebula	Cone Nebula
Examine how colored filters really work on colored light.	Look at structures in a planetary nebula using filters.	Look at structures in a planetary nebula using filters.	Look at structures in hydrogen gas and dust clouds using filters
Horsehead Nebula	Omega Centauri	Stingray Nebula	Crab Nebula
Look at structures in hydrogen gas and dust clouds using filters.	Look at different types of stars in a globular cluster using filters.	Look at structures in a very young planetary nebula using filters.	Look at structures in a supernova remnant using filters.
M5 Globular Cluster	47 Tucanae Star Cluster	NGC 6822	NGC 3603
Look at different types of stars in a globular cluster using filters.	Look at different types of stars in a globular cluster using filters.	Look at different types of stars in an irregular galaxy in the local group using color filters.	Look at structures in a star cluster and hydrogen gas nebula region using color filters.
Jewel Box	Rosette Nebula	NGC 5189 Weird Planetary Nebula	30 Daradus (NGC 2070)
Look at stars in an open cluster with one odd-ball orange star using filters.	Look at structures in a star forming region with a nebula of hydrogen gas using color filters.	Look at structures in a planetary nebula using filters.	Look at structures in a star forming region using your filters.
NGC 6520 and Dust Cloud Barnard 86	Gas Pillars in M16- Eagle Nebula	Supernoa 1987a Rings
Look at structures in a star forming region and dust cloud using color filters.	Look at star forming region  using color filters	Look at star death through color filters