I was able to shrink my sketch version to merely 402 (386) characters within 80 columns. 
Dunno if that’s enough for a tweet, but you can take a look at it running online: 
Also leaving a copy of it in this forum: 
R=42,G=84,B=128,V=600,S=32
I=Int32Array,A=new I(V*V),K=new I(B),f=0
setup=_=>{createCanvas(V,V)
pixelDensity(1).loadPixels(s=sin)
p=new I(pixels.buffer)
for(y=0;y<V;++y)for(x=0;x<V;)A[V*y+x]=B/4*(s(x/S)+cos(y/S)+s(sqrt(x*x+++y*y)/S))
for(i=0;i<B;)u=B*s(.12*i),
K[i]=color(R+u,G+B*s(PI/50*i+++.79),B+u).levels.reduce((a,v,i)=>v<<i*8|a,0)}
draw=_=>{++f
for(i=0;i<V*V;)p[i]=K[f+A[i++]&B-1]
updatePixels()}