Can the new HatchShading and StippleShading plotstyles be used without color?


I wanted (PlotStyles) HatchShading or StippleShading for figures that will be printed in black and white, but these options end up color by default. I tried combining with a GrayTones ColorFunction, like so:

scap = {Sin[#1] Cos[#2], Sin[#1] Sin[#2], Cos[#1]} & ; {ParametricPlot3D[ {Sin[t]^2 scap[t, p]}, {t, 0, Pi}, {p, 0, 2 Pi}   , Lighting -> "Accent"   , ColorFunction -> "GrayTones"   ],  ParametricPlot3D[ {Sin[t]^2 scap[t, p]}, {t, 0, Pi}, {p, 0, 2 Pi}   , Lighting -> "Accent"   , ColorFunction -> "GrayTones"   , PlotStyle -> HatchShading[0.7, Black]   ],  ParametricPlot3D[ {Sin[t]^2 scap[t, p]}, {t, 0, Pi}, {p, 0, 2 Pi}   , Lighting -> "Accent"   , ColorFunction -> "GrayTones"   , PlotStyle -> StippleShading[]   ]} 

but the GrayTones ColorFunction seems to be ignored when using these PlotStyles.

some plots

Is there a way to avoid the use of a color background in the plot image when using HatchShading or StippleShading?