Remove monocolor blend masks from showcases (#137)

data/magic-m15-showcase-zendikar.mse-style/style

@@ -63,8 +63,8 @@ init script:
 	land_template := { template_prefix[type] + (if input == "a" then "c" else input) + template_suffix[type] }
 	# Use land templates for previews because they show more contrast
 	hybrid_previews := "land,hybrid"
-	crown_background := { color_background(type:"crown",     base_hybrid:card_hybrid) }
-	hedron_background := { color_background(type:"card2",     base_hybrid:card_hybrid) }
+	crown_background :=		{ color_background(type:"crown",	base_hybrid:card_hybrid,	hybrid_blend: "white",	artifact_blend: "black",	multicolor_blend: "white") }
+	hedron_background :=	{ color_background(type:"card2",	base_hybrid:card_hybrid,	hybrid_blend: "white",	artifact_blend: "black",	multicolor_blend: "black") }
 
 	# Use the normal tap symbol
 	mana_t := {