Jeffy goes MOOOOO! ... or not.

reset
make "x 0
make "r 255
make "g 0
make "b 0
penwidth 3
repeat 1000 [
  color [:r :g :b]
  lt :x % 20
  fw 1
  if and and :r = 255 :g = 0 :b > 0 [ 
    make "b :b - 1
  ]
  if and and :r = 255 :g < 255 :b = 0 [
    make "g :g + 1
  ]
  if and and :r > 0 :g = 255 :b = 0 [
    make "r :r - 1
  ]
  if and and :r = 0 :g = 255 :b < 255 [
    make "b :b + 1
  ]
  if and and :r = 0 :g > 0 :b = 255 [
    make "g :g - 1
  ]
  if and and :r < 0 :g = 0 :b = 255 [
    make "r :r + 1
  ]
  color [:r :g :b]
  rt :x % 30
  fw 1
  if and and :r = 255 :g = 0 and :b > 0 [ 
    make "b :b - 1
  ]
  if and and :r = 255 :g < 255 and :b = 0 [
    make "g :g + 1
  ]
  if and and :r > 0 :g = 255 :b = 0 [
    make "r :r - 1
  ]
  if and and :r = 0 :g = 255 :b < 255 [
    make "b :b + 1
  ]
  if and and :r = 0 :g > 0 :b = 255 [
    make "g :g - 1
  ]
  if and and :r < 0 :g = 0 :b = 255 [
    make "r :r + 1
  ]
  make "x :x + 1
]