Reference the code below which discretises a geometric region (as shown in the accompanying graphic), I want to display node and face numbers with node numbers in one colour and face numbers in a different colour. However, I haven't been able to find a way of achieving this.

Also, I'd like to be able to control the default (blue) solid fill that's used to highlight the discretised region - ideally being able to specify no fill. This becomes an issue when I choose different fill colours for the cells and apply Opacity (low Opacity values result in the fill tending to the default blue rather than being almost opaque).

Any suggestions would be much appreciated.

Thanks in anticipation,

Ian

Region[Polygon[{{0, 0}, {15, 0}, {15, 2}, {10, 2}, {5, 5}, {0, 5}}]] //

  DiscretizeRegion[#
    , Frame -> True
    , FrameTicks -> {x, x} /. x -> Range[-20, 20, 1]
    , FrameLabel -> {"x-coordinate (m)", "y-coordinate (m)"}
    , GridLines -> {x, x} /. x -> Range[-20, 20]
    , GridLinesStyle -> Directive[LightGray, Thin]
    , ImageSize -> Full
    , MaxCellMeasure -> 0.5
    , MeshCellLabel -> {0 -> "Index", 2 -> "Index"}
    , MeshCellStyle -> {{2, All} -> 
       Directive[RGBColor[0, 0.75, 0.5, opacity]], {2, 1} -> {Yellow, 
        Opacity[opacity]}, {1, All} -> 
       Directive[GrayLevel[0.975], Thickness[Medium]], {0, All} -> 
       Directive[Red, PointSize[Large]]}
    (*,Method\[Rule]{"AxesInFront"\[Rule]True,
    "GridLinesInFront"\[Rule]True}*)
    , PlotRangePadding -> 1
    ] & /. {opacity -> 0.75(*0=transparent, 1=solid fill*)}