[B: <X>,<Y>,<W>,<H>,<Color> ]
[B: <X1>,<Y1>,<W1>,<H1>,<Color>,<X2>,<Y2>,<W2>,<H2> ]
[B: <X1>,<Y1>,<W1>,<H1>,<Color>,<X2>,<Y2>,<W2>,<H2>,<X3>,<Y3>,<W3>,<H3>, … ]

Block Fill

A rectangular field is filled with the colour <Color>. If <Color> is missing, the field will be filled with the colour of its upper left corner.

You can give more sets of the   <X>,<Y>,<W>,<H> parameters in the modifier: all rectangles will be filled with the same colour. Only the 4 coordinates should be repeated, not the <Color> parameter.