diff --git a/src/geometry_header.F90 b/src/geometry_header.F90
index aa1fcca5f6..fbcf0353a9 100644
--- a/src/geometry_header.F90
+++ b/src/geometry_header.F90
@@ -64,7 +64,6 @@ module geometry_header
           & surfaces(:)    ! List of surfaces bounding cell -- note that
                            ! parentheses, union, etc operators will be listed
                            ! here too
-     integer, allocatable :: rgb(:) ! plotting color
   end type Cell
 
   ! array index of universe 0
diff --git a/src/input_xml.F90 b/src/input_xml.F90
index 9b806ade83..36ff24fd36 100644
--- a/src/input_xml.F90
+++ b/src/input_xml.F90
@@ -261,14 +261,6 @@ contains
        c % material = cell_(i) % material
        c % fill     = cell_(i) % fill
 
-       ! Set plot color
-       if (plotting) then
-          allocate(c % rgb(3))
-          c % rgb(1) = prn()*255
-          c % rgb(2) = prn()*255
-          c % rgb(3) = prn()*255
-       end if
-
        ! Check to make sure that either material or fill was specified
        if (c % material == 0 .and. c % fill == 0) then
           message = "Neither material nor fill was specified for cell " // & 
@@ -539,14 +531,6 @@ contains
        ! Copy material id
        m % id = material_(i) % id
 
-       ! Set plot color
-       if (plotting) then
-          allocate(m % rgb(3))
-          m % rgb(1) = prn()*255
-          m % rgb(2) = prn()*255
-          m % rgb(3) = prn()*255
-       end if
-
        ! Copy density -- the default value for the units is given in the
        ! material_t.xml file and doesn't need to be specified here, hence case
        ! default results in an error.
@@ -1143,6 +1127,7 @@ contains
       pl % id       = plot_(i) % id
       pl % aspect   = plot_(i) % aspect
 
+      ! Copy plot pixel size
       if (size(plot_(i) % pixels) == 2) then
         pl % pixels = plot_(i) % pixels
       else
@@ -1150,17 +1135,18 @@ contains
         call fatal_error()
       end if
 
-      select case (plot_(i) % color)
-        case ("cell")
-          pl % color = PLOT_COLOR_CELLS
-        case ("mat")
-          pl % color = PLOT_COLOR_MATS
-        case default
-          message = "Unsupported plot color '" // plot_(i) % color &
-                    // "' in plot " // trim(to_str(pl % id))
+      ! Copy plot background color
+      if (size(plot_(i) % background) == 3) then
+         pl % not_found % rgb = plot_(i) % background
+      else if (size(plot_(i) % background) == 0) then
+         pl % not_found % rgb = (/ 0, 0, 0 /)
+      else
+          message = "Bad background RGB " &
+                    // "in plot " // trim(to_str(pl % id))
           call fatal_error()
-      end select
+      end if
 
+      ! Copy plot type
       select case (plot_(i) % type)
         case ("slice")
           pl % type = PLOT_TYPE_SLICE
@@ -1172,6 +1158,7 @@ contains
           call fatal_error()
       end select
 
+      ! Copy plot basis
       select case (plot_(i) % basis)
         case ("xy")
           pl % basis = PLOT_BASIS_XY
@@ -1206,6 +1193,34 @@ contains
           call fatal_error()
       end if
 
+      ! Copy plot color type and initialize all colors randomly
+      select case (plot_(i) % color)
+        case ("cell")
+
+          pl % color_by = PLOT_COLOR_CELLS
+          allocate(pl % colors(n_cells))
+          do j = 1, n_cells
+            pl % colors(j) % rgb(1) = prn()*255
+            pl % colors(j) % rgb(2) = prn()*255
+            pl % colors(j) % rgb(3) = prn()*255
+          end do
+
+        case ("mat")
+
+          pl % color_by = PLOT_COLOR_MATS
+          allocate(pl % colors(n_materials))
+          do j = 1, n_materials
+            pl % colors(j) % rgb(1) = prn()*255
+            pl % colors(j) % rgb(2) = prn()*255
+            pl % colors(j) % rgb(3) = prn()*255
+          end do
+
+        case default
+          message = "Unsupported plot color type '" // plot_(i) % color &
+                    // "' in plot " // trim(to_str(pl % id))
+          call fatal_error()
+      end select
+
       ! Copy user specified colors
       n_cols = size(plot_(i) % col_spec_)
       do j = 1, n_cols
@@ -1217,24 +1232,20 @@ contains
 
         col_id = plot_(i) % col_spec_(j) % id
 
-        if (pl % color == PLOT_COLOR_CELLS) then
+        if (pl % color_by == PLOT_COLOR_CELLS) then
 
           if (dict_has_key(cell_dict, col_id)) then
-            cells(col_id) % rgb(1) = plot_(i) % col_spec_(j) % rgb(1)
-            cells(col_id) % rgb(2) = plot_(i) % col_spec_(j) % rgb(2)
-            cells(col_id) % rgb(3) = plot_(i) % col_spec_(j) % rgb(3)
+            pl % colors(col_id) % rgb = plot_(i) % col_spec_(j) % rgb
           else
             message = "Could not find cell " // trim(to_str(col_id)) // &
                       " specified in plot " // trim(to_str(pl % id))
             call fatal_error()
           end if
 
-        else if (pl % color == PLOT_COLOR_MATS) then
+        else if (pl % color_by == PLOT_COLOR_MATS) then
 
           if (dict_has_key(material_dict, col_id)) then
-            materials(col_id) % rgb(1) = plot_(i) % col_spec_(j) % rgb(1)
-            materials(col_id) % rgb(2) = plot_(i) % col_spec_(j) % rgb(2)
-            materials(col_id) % rgb(3) = plot_(i) % col_spec_(j) % rgb(3)
+            pl % colors(col_id) % rgb = plot_(i) % col_spec_(j) % rgb
           else
             message = "Could not find material " // trim(to_str(col_id)) // &
                       " specified in plot " // trim(to_str(pl % id))
@@ -1245,6 +1256,22 @@ contains
 
       end do
 
+      ! Alter colors based on mask information
+      if (size(plot_(i) % mask_) /= 1) then
+        message = "Mutliple masks" // &
+                  " specified in plot " // trim(to_str(pl % id))
+        call fatal_error()
+      else
+          do j=1,size(pl % colors)
+            if (.not. any(j .eq. plot_(i) % mask_(1) % components)) then
+              pl % colors(j) % rgb = plot_(i) % mask_(1) % background
+            end if
+          end do
+      end if
+      
+      
+
+
     end do
 
   end subroutine read_plots_xml
diff --git a/src/material_header.F90 b/src/material_header.F90
index d8e9ca4ea2..916578923b 100644
--- a/src/material_header.F90
+++ b/src/material_header.F90
@@ -21,8 +21,6 @@ module material_header
      character(12) :: sab_name        ! name of S(a,b) table
      integer       :: sab_table   = 0 ! index in sab_tables
      integer       :: sab_nuclide = 0 ! index of nuclide which has S(a,b) table
-
-     integer, allocatable :: rgb(:) ! plotting color
   end type Material
 
 end module material_header
diff --git a/src/output.F90 b/src/output.F90
index c4209ace13..0876d266c2 100644
--- a/src/output.F90
+++ b/src/output.F90
@@ -914,7 +914,7 @@ contains
 
         write(ou,100) "Width:", trim(to_str(pl % width(1))) // &
              " " // trim(to_str(pl % width(2)))
-        write(ou,100) "Coloring:", trim(to_str(pl % color))
+        write(ou,100) "Coloring:", trim(to_str(pl % color_by))
         write(ou,100) "Basis:", trim(to_str(pl % basis))
         write(ou,100) "Pixels:", trim(to_str(pl % pixels(1))) // " " // &
                                  trim(to_str(pl % pixels(2)))
@@ -924,7 +924,7 @@ contains
         write(ou,100) "Width:", trim(to_str(pl % width(1))) // &
              " " // trim(to_str(pl % width(2))) // " " &
                  // trim(to_str(pl % width(3)))
-        write(ou,100) "Coloring:", trim(to_str(pl % color))
+        write(ou,100) "Coloring:", trim(to_str(pl % color_by))
         write(ou,100) "Ray Spacing:", trim(to_str(pl % aspect))
 
       end if
diff --git a/src/plot.F90 b/src/plot.F90
index 2f82b9dd8f..ef93fecf4f 100644
--- a/src/plot.F90
+++ b/src/plot.F90
@@ -106,19 +106,19 @@ contains
         call find_cell(found_cell)
 
         if (.not. found_cell) then
-          r = 255
-          g = 255
-          b = 255
+          r = pl % not_found % rgb(1)
+          g = pl % not_found % rgb(2)
+          b = pl % not_found % rgb(3)
         else
-          c => cells(p % coord % cell)
-          if (pl % color == PLOT_COLOR_MATS) then
-            r = materials(c % material) % rgb(1)
-            g = materials(c % material) % rgb(2)
-            b = materials(c % material) % rgb(3)
-          else if (pl % color == PLOT_COLOR_CELLS) then
-            r = c % rgb(1)
-            g = c % rgb(2)
-            b = c % rgb(3)
+          if (pl % color_by == PLOT_COLOR_MATS) then
+            c => cells(p % coord % cell)
+            r = pl % colors(c % material) % rgb(1)
+            g = pl % colors(c % material) % rgb(2)
+            b = pl % colors(c % material) % rgb(3)
+          else if (pl % color_by == PLOT_COLOR_CELLS) then
+            r = pl % colors(p % coord % cell) % rgb(1)
+            g = pl % colors(p % coord % cell) % rgb(2)
+            b = pl % colors(p % coord % cell) % rgb(3)
           else
             r = 0
             g = 0
diff --git a/src/plot_header.F90 b/src/plot_header.F90
index bfe6f9b071..b2f849ea99 100644
--- a/src/plot_header.F90
+++ b/src/plot_header.F90
@@ -3,18 +3,28 @@ module plot_header
   implicit none
 
 !===============================================================================
-! PLOT hold plot information
+! ObjectColor holds color information for plotted objects
+!===============================================================================
+
+  type ObjectColor
+    integer :: rgb(3)
+  end type ObjectColor
+
+!===============================================================================
+! PLOT holds plot information
 !===============================================================================
 
   type Plot
      integer :: id                    ! Unique ID
      integer :: type                  ! Type
-     integer :: color                 ! quantity to color regions by
+     integer :: color_by              ! quantity to color regions by
      real(8) :: origin(3)             ! xyz center of plot location
      real(8) :: aspect                ! spacing between rays in raytracer
      real(8) :: width(3)              ! xyz widths of plot
      integer :: basis                 ! direction of plot slice 
      integer :: pixels(2)             ! pixel width/height of plot slice
+     type(ObjectColor) :: not_found   ! color for positions where no cell found
+     type(ObjectColor),allocatable :: colors(:) ! colors of cells/mats
   end type Plot
 
   integer :: PLOT_TYPE_SLICE = 1
diff --git a/src/xml-fortran/templates/plots_t.xml b/src/xml-fortran/templates/plots_t.xml
index f372411922..e3f6903fe6 100644
--- a/src/xml-fortran/templates/plots_t.xml
+++ b/src/xml-fortran/templates/plots_t.xml
@@ -8,6 +8,11 @@
     <component name="rgb" type="integer-array" />
   </typedef>
 
+  <typedef name="mask_xml">
+    <component name="components" type="integer-array" />
+    <component name="background" type="integer-array" />
+  </typedef>
+
   <typedef name="plot_xml">
     <component name="id" type="integer" />
     <component name="type" type="word" length="10" default="'slice'"/>
@@ -17,7 +22,9 @@
     <component name="basis" type="word" length="3" default="'xy'" />
     <component name="pixels" type="integer-array" />
     <component name="aspect" type="double" default="0.1" />
+    <component name="background" type="integer-array"/>
     <component name="col_spec_" tag="col_spec" type="col_spec_xml" dimension="1" />
+    <component name="mask_" tag="mask" type="mask_xml" dimension="1" />
   </typedef>
 
   <variable name="plot_" tag="plot" type="plot_xml" dimension="1" />