Some important details as to when "S'char shabbos" applies.
understanding the two views with "דרך לכלוך" (coloring destructively). (Wiping one's hands on a towel from grape juice, blood, pomegranate, colored ices, etc.);
Important Review: How to Handle a Vase with Flowers on Shabbos;
What Exactly Is It All About in Reference to מצות (Mitzvos) and איסורים (Issurim)? What Did We Learn Out From the פסוקים (Pesukim)?;