picture1.scalemode=VbPixels
 picture1.scale(0,picture1.height)-(picture1.width,0)

dim x  as integer
dim y as integer
dim color as long
dim incolor (zuersetzende Farbe)
dim outcolor (ersetzende Farbe)
incolor=&H8000000B&           'Grau
outcolor=vbred                           'Rot
for x=0 to picture1.width
       for y=0 to picture1.heigth
           farbe=picture1.point(x,y)
           if farbe=incolor  then
                picture1.pset(x,y),outcolor
           end if
       next
next

if color>=incolormin and color<=incolormax then
      picture1.pset(x,y),outcolor
end if