Here are a couple more articles/guides for observing Mars courtesy of Agena Astro. They can be found in the ARTICLES/GUIDES section within the Agena Astro website, as well as many other informative articles:

https://agenaastro.com/articles/guides

First is the observing guide by Brian Ventrudo, updated 2020. It is filled with very good basic information and tips covering many aspects of observing The Red Planet:

https://agenaastro.com/articles/mars-observing-guide.html

The second writeup I want to mention is a guide covering colored planetary filters by Tanmoy Laskar and Manish Panjwani, updated 2019. Included is a chart of Wratten numbers and colors, with columns for each planet and the uses for each color filter. There are also filter specific descriptions that include transmission percentages, etc:

https://agenaastro.com/articles/choosing-a-color-planetary-filter.html

Based on what I have read over the years on other websites, there appears to be a gross misunderstanding of colored filter uses. What filters are used for are to isolate specific observable phenomena, and this chart is a good guide for choosing specific colored filters for isolating those features you want to observe.

Ed D