I got a yellow!
I used a mix of boletus (which have pores/tubes to release spores instead of gills).
I used Boletus mirabilis and Boletus zelleri with 1 scoop alum and 2 scoops cream of tartar.
top left: Polyozellus + copper penny
top right: Copper Penny Blue (pennies + ammonia)
lover left: Boletus + alum + cream of tartar
lower right: Paxillus + alum + cream of tartar