SCREEN 12: CLS
drn% = 1

DO
c% = c% + 1: IF c% > 15 THEN c% = 1
GOSUB newpal
PALETTE c%, pl&
IF RND * 1000 > 999 THEN drn% = 1
ON drn% GOSUB drctn1
LOOP

drctn1:
x = x + 1: IF x > 319 THEN x = 0: y = y + 1
IF y > 199 THEN y = 0
PSET (x, y), y
RETURN

newpal:
rd = rd + RND * .2 - .1
IF rd < -1 THEN rd = -1
IF rd > 1 THEN rd = 1
gd = gd + RND * .2 - .1
IF gd < -1 THEN gd = -1
IF gd > 1 THEN gd = 1
bd = bd + RND * .2 - .1
IF bd < -1 THEN bd = -1
IF bd > 1 THEN bd = 1
r = r + rd
IF r < 16 THEN r = 16
IF r > 63 THEN r = 63
g = g + gd
IF g < 16 THEN g = 16
IF g > 63 THEN g = 63
b = b + bd
IF b < 16 THEN b = 16
IF b > 63 THEN b = 63
pl& = FIX(r) + FIX(g) * 256 + FIX(b) * 65536
RETURN