This can colour you text in a rainbow sequence. Just load into your remotes (Alt+R).

When loaded right click and then select under "rainbow" one of for options.

"text On" will colour the font in a rainbow sequence

"text background On" will colour the font and background colour in a rainbow sequence.

"Colour Off" turns both of these colours off.

note that "text On" and "text background On" can only colour a certain number of characters and will uncolour the text if it is too much.

*Updates
Slightly recoded
Changed some global to local variables
Corrected a mistake where a variable wudnt be unset (this also corrected the rainbow glitch where it would miss a space and colour after the 6th colour in the pattern)
Just improved efficiency

on *:INPUT:*:{
  if (%rainbowtexton == 1) && ($left($1,1) != /) {
    var %r1 1
    var %nintext $len($1-) + 1
    while (%r1 < %nintext) {
      if ($mid($1-,%r1,1) != $chr(32)) { var %msgrbw $addtok(%msgrbw,04 $+ $mid($1-,%r1,1),0) }
      else { var %msgrbw %msgrbw $chr(32) }
      inc %r1

      if ($mid($1-,%r1,1) != $chr(32)) { var %msgrbw $addtok(%msgrbw,07 $+ $mid($1-,%r1,1),0) }
      else { var %msgrbw %msgrbw $chr(32) }
      inc %r1

      if ($mid($1-,%r1,1) != $chr(32)) { var %msgrbw $addtok(%msgrbw,08 $+ $mid($1-,%r1,1),0) }
      else { var %msgrbw %msgrbw $chr(32) }
      inc %r1

      if ($mid($1-,%r1,1) != $chr(32)) { var %msgrbw $addtok(%msgrbw,09 $+ $mid($1-,%r1,1),0) }
      else { var %msgrbw %msgrbw $chr(32) }
      inc %r1

      if ($mid($1-,%r1,1) != $chr(32)) { var %msgrbw $addtok(%msgrbw,12 $+ $mid($1-,%r1,1),0) }
      else { var %msgrbw %msgrbw $chr(32) }
      inc %r1

      if ($mid($1-,%r1,1) != $chr(32)) { var %msgrbw $addtok(%msgrbw,06 $+ $mid($1-,%r1,1),0) }
      else { var %msgrbw %msgrbw $chr(32) }
      inc %r1

      if ($mid($1-,%r1,1) != $chr(32)) { var %msgrbw $addtok(%msgrbw,13 $+ $mid($1-,%r1,1),0) }
      else { var %msgrbw %msgrbw $chr(32) }
      inc %r1
    }
    say %msgrbw
    haltdef
  }

  elseif (%rainbowtextandbackgroundon == 1)  && ($left($1,1) != /) {
    var %r2 1
    var %nintext2 $len($1-) + 1
    while (%r2 < %nintext2) {

      if ($mid($1-,%r2,1) != $chr(32)) { var %msgrbw2 $addtok(%msgrbw2,6 $+ $chr(44) $+ 04 $+ $mid($1-,%r2,1),0) }
      else { var %msgrbw2 %msgrbw2 $+ 6,04 $chr(32) }
      inc %r2

      if ($mid($1-,%r2,1) != $chr(32)) { var %msgrbw2 $addtok(%msgrbw2,13 $+ $chr(44) $+ 07 $+ $mid($1-,%r2,1),0) }
      else { var %msgrbw2 %msgrbw2 $+ 13,07 $chr(32) }
      inc %r2

      if ($mid($1-,%r2,1) != $chr(32)) { var %msgrbw2 $addtok(%msgrbw2,12 $+ $chr(44) $+ 08 $+ $mid($1-,%r2,1),0) }
      else { var %msgrbw2 %msgrbw2 $+ 12,08 $chr(32) }
      inc %r2

      if ($mid($1-,%r2,1) != $chr(32)) { var %msgrbw2 $addtok(%msgrbw2,3 $+ $chr(44) $+ 09 $+ $mid($1-,%r2,1),0) }
      else { var %msgrbw2 %msgrbw2 $+ 3,09 $chr(32) }
      inc %r2

      if ($mid($1-,%r2,1) != $chr(32)) { var %msgrbw2 $addtok(%msgrbw2,8 $+ $chr(44) $+ 12 $+ $mid($1-,%r2,1),0) }
      else { var %msgrbw2 %msgrbw2 $+ 8,12 $chr(32) }
      inc %r2

      if ($mid($1-,%r2,1) != $chr(32)) { var %msgrbw2 $addtok(%msgrbw2,7 $+ $chr(44) $+ 13 $+ $mid($1-,%r2,1),0) }
      else { var %msgrbw2 %msgrbw2 $+ 7,13 $chr(32) }
      inc %r2

      if ($mid($1-,%r2,1) != $chr(32)) { var %msgrbw2 $addtok(%msgrbw2,4 $+ $chr(44) $+ 06 $+ $mid($1-,%r2,1),0) }
      else { var %msgrbw2 %msgrbw2 $+ 4,06 $chr(32) }
      inc %r2
    }
    say %msgrbw2
    haltdef
  }

}

menu channel {
  -
  Rainbow
  .text On:{
  unset %rainbowtextandbackgroundon
  set %rainbowtexton 1
  ;echo -a Rainbow text turned on
  }
  .text + background On:{
  unset %rainbowtexton
  set %rainbowtextandbackgroundon 1
  ;echo -a Rainbow text and background colour turned on
  }
  .Colour Off:{
  unset %rainbowtexton
  unset %rainbowtextandbackgroundon
  ;echo -a Rainbow text, and Rainbow text with background colour turned off
  }
  -
}