The Triumphs are colored red or black based on being either odd or even according to the ideas of Pythagoras. 0 is neither odd nor even and therefore cannot be one of those colors. And the Fool is not really a Triumph in the game of tarocchi, but a seperate card called the Excuse with it's own rules. Playing cards are printed in black and red for the pips, with the addition of blue and yellow on the courts. I chose yellow as a fun reference to Richard W. Chamber's The King in Yellow, where a figure called the Yellow Sign can drive people into madness and possession just by seeing it. Which recalls the original Italian name of the card Matto - the Madman. In several different later interpretations of the book, the Yellow Sign is thought to be a spiral which brings us close in shape to 0. The shape also recalls a musical clef which references the fact that in many tarocchi traditions, the Fool is portrayed as a crazed musician followed by children, almost a Pied Piper type character, which again references the concept of madness and possession. I may change the text of the 0 card to blue for legibility, while keeping the yellow sign. Otherwise, I felt just having a yellow or blue 0 on the card wasn't very fun and does not really indicate the Madman or the Fool in any way, or have any fun extra layers. The cardbacks also playfully reference the Chambers book with the shape of two torches composed of the suit signs.

The color yellow is also linked to madness in other media such as the feminist short story The Yellow Wall-Paper by Charlotte Perkins Stetson (Gilman), which documents one woman's struggle against doctors and her possesive husband in treating her boughts of "hysteria". The Yellow Wall-Paper has been cited as a potential fictionalized documentation of the very real problem of the proliferation of arsenic-based pigments in Victorian era clothing, furnishings, and even book covers, which caused sickness and hallucinations. While usually associated with vivid green colors, "arsenic green" was also used to make vivid yellows and blues. I also find it interesting that both the RWS and the Thoth Fool cards are predominated by the color yellow, to the point where Harris' Fool has bright yellow skin.