This is based on the mesh star drawing from Johnny McGibbitts in the BASIC on the ZX Spectrum group which I converted to layer 2, ran 10 iterations with different numbers and palette-cycled each one.

Here is the code if you want to play with it:

10 RUN AT 3: LAYER 2,1: PALETTE DIM 8: BORDER 0: PAPER 227: CLS :s=90: PROC pal(4): FOR i=0 TO s STEP 5: INK %i: PLOT i+128,96: PROC xtra(): DRAW -i,s-i: PROC xtra(): DRAW -i,i-s: PROC xtra(): DRAW i,i-s: PROC xtra(): DRAW i,s-i:%i=%i+1 AND (i<255): NEXT i
20 PROC cycle(3): GO TO 20
100 DEFPROC pal(%p)
110 BANK 20 ERASE : FOR %a=0 TO 255 STEP %p: BANK 20 POKE %a,%a: BANK 20 POKE %a+256,%a: NEXT %a
120 ENDPROC
130 DEFPROC cycle(%c)
140 FOR %a=0 TO 255 STEP %c: LAYER PALETTE 0 BANK 20,%a: LAYER PALETTE 0,227,0: SPRITE MOVE INT : NEXT %a
150 ENDPROC
160 DEFPROC xtra()
170 ;DRAW 5,5,5: DRAW -5,-5,-5
180 ENDPROC

Uwe Geiken made a post showing a simple fractal in ZX Basic (in the BASIC group) and I converted it to the ZX Next, changing the ink colour each iteration then palette-cycling it. I slowed the animation down with PAUSE so it was captured better: