A snippet that lets you scroll around to get the rgb value you need. There is a little bmp image preview that displays the color as you scroll. Once you have obtained your RGB value, click clipboard and it copies the rgb code.

To open: /rgbview

Updates:

Added an RGB info box with the HEX value and RGB value

dialog getrgbd {
  title "RGB viewer"
  size -1 -1 251 142
  option pixels
  scroll "", 1, 41 6 192 13, range 0 255 horizontal bottom
  text "Red:", 2, 1 4 33 16
  text "Blue:", 3, 0 23 33 16
  scroll "", 4, 41 24 192 13, range 0 255 horizontal bottom
  scroll "", 6, 41 42 192 13, range 0 255 horizontal bottom
  text "Green:", 7, 0 41 36 16
  button "Exit", 8, 97 113 45 25, ok cancel
  button "Clipboard", 9, 142 113 63 25
  icon 10, 1 67 91 77
  box "RGB info", 11, 97 52 144 55
  text "RGB ", 12, 103 68 50 16
  text "HEX", 13, 102 87 50 14
  text "", 14, 166 68 67 16
  text "", 15, 167 87 66 14
}

alias getrgb {
  window -phn +b @prev -1 -1 80 50
  drawfill -r @prev $rgb($1,$2,$3) 1 1 1
  drawsave @prev getrgb.bmp
  window -c @prev
}

on *:dialog:*:*:*:{ 
  if ($dname = getrgbd) { 
    if ($devent = scroll) { 
      var %z = $did($dname,1).sel $did($dname,6).sel $did($dname,4).sel
      getrgb %z
      did -g $dname 10 getrgb.bmp
      did -ra $dname 14 $+($did($dname,1).sel,$chr(44),$did($dname,6).sel,$chr(44),$did($dname,4).sel)
      did -ra $dname 15 $+($chr(35),$base($rgb($token(%z,1,32),$token(%z,2,32),$token(%z,3,32)),10,16))
    }
  }
  if ($devent = sclick) { 
    if ($did = 9) { clipboard $+($did($dname,1).sel,$chr(44),$did($dname,6).sel,$chr(44),$did($dname,4).sel) }
  }
}
alias rgbview { if (!$dialog(getrgbd)) { dialog -m getrgbd getrgbd }