This script serves a very basic function that is already included in mirc's color dialogs. The basic function of this script is to change your background and foreground(normal text) colors.
The reason I am posting this is to demonstrate how to create a color pallet with mirc's drawfill/drawsave functions, and then use it to spice up your dialogs with a little COLOR :)
The jewel of this script is the MakeColorIcons alias. This alias creates a small bitmap image for each of the 16 colors available in mirc.
If you look at this line - ->

window  -hBpf +d @MakeColorIcons -1 -1 68 68

The last two numbers determine the size of the bmp. 68 x 68 is equal to 34 x 34 in dialogs.
You can change these two numbers, in conjunction with the last two numbers in the drawfill line, to change the file size/shape.
In addition, you can also use $rgb() in the drawfill line, to create custom colors.
Basically, anything you can draw in a window, can be saved with drawsave and used in dialogs or elsewhere in mirc.
From here you just need to add a icon spot in your dialog and add your color with did -g dialogname N pathtofile\filename.bmp

:)

alias MakeColorIcons {
  var %c 0
  if (!$isdir($+($mircdir,ColorIcon))) { mkdir ColorIcon }
  while (%c <= 15) {
    if (!$window(@MakeColorIcons)) { window  -hBpf +d @MakeColorIcons -1 -1 68 68 }
    drawfill @MakeColorIcons %c %c 0 0 68 68
    if (!$isfile($+(ColorIcon\,ColorIcon,%c,.bmp))) { drawsave @MakeColorIcons $qt($+($mircdir,ColorIcon\,ColorIcon,%c,.bmp)) }
    inc %c
  }
  window -c @MakeColorIcons
}
alias ColorPicker {
  if (!$dialog(ColorPicker)) { dialog -m ColorPicker ColorPicker }
  else { dialog -v ColorPicker ColorPicker }
}
dialog ColorPicker {
  title "Color Picker"
  size -1 -1 90 88
  option dbu
  icon 1, 2 2 8 8
  icon 2, 13 2 8 8
  icon 3, 24 2 8 8
  icon 4, 35 2 8 8
  icon 5, 46 2 8 8
  icon 6, 57 2 8 8
  icon 7, 68 2 8 8
  icon 8, 79 2 8 8
  icon 9, 2 15 8 8
  icon 10, 13 15 8 8
  icon 11, 24 15 8 8
  icon 12, 35 15 8 8
  icon 13, 46 15 8 8
  icon 14, 57 15 8 8
  icon 15, 68 15 8 8
  icon 16, 79 15 8 8
  button "", 17, 4 4 4 4
  button "", 18, 15 4 4 4
  button "", 19, 26 4 4 4
  button "", 20, 37 4 4 4
  button "", 21, 48 4 4 4
  button "", 22, 59 4 4 4
  button "", 23, 70 4 4 4
  button "", 24, 81 4 4 4
  button "", 25, 4 17 4 4
  button "", 26, 15 17 4 4
  button "", 27, 26 17 4 4
  button "", 28, 37 17 4 4
  button "", 29, 48 17 4 4
  button "", 30, 59 17 4 4
  button "", 31, 70 17 4 4
  button "", 32, 81 17 4 4
  icon 33, 6 36 34 34
  icon 34, 50 36 34 34
  radio "Foreground", 35, 6 24 37 10
  radio "Background", 36, 48 24 37 10
  button "Close", 37, 56 74 29 12, cancel
  button "Accept", 38, 5 74 29 12
}
On *:Dialog:ColorPicker:Close:*: {
  unset %ColorPicker*
}
On *:Dialog:ColorPicker:Sclick:*: {
  if ($did >= 17) && ($did <= 32) {
    if ($did(ColorPicker,35).state == 1) { 
      did -g ColorPicker 33 $+(ColorIcon\,ColorIcon,$calc($did - 17),.bmp)
      set %ColorPickerFG $calc($did - 17)
    }
    if ($did(ColorPicker,36).state == 1) { 
      did -g ColorPicker 34 $+(ColorIcon\,ColorIcon,$calc($did - 17),.bmp)
      set %ColorPickerBG $calc($did - 17)
    }
  }
  if ($did == 38) {
    color normal text %ColorPickerFG
    color background %ColorPickerBG
  }
}
On *:Dialog:ColorPicker:init:*: {
  MakeColorIcons
  var %c = 0
  while %c <= 15 {
    did -g ColorPicker $calc(%c + 1) $+(ColorIcon\,ColorIcon,%c,.bmp)
    inc %c
  }
  did -c ColorPicker 35
  set %ColorPickerFG $color(normal text)
  set %ColorPickerBG $color(background)
  did -g ColorPicker 33 $+(ColorIcon\ColorIcon,$color(normal text),.bmp)
  did -g ColorPicker 34 $+(ColorIcon\ColorIcon,$color(background),.bmp)
}
menu * {
 ColorPicker:ColorPicker
}