Transparency Pixel colour for Sprites on HP Prime

[matalog]

Hey, thanks for the continuous replies, I do appreciate it!

I had a go at getting them moving in front of a background.

EXPORT vispends()
BEGIN
DIMGROB_P(G1,320,240);
DIMGROB_P(G4,320,240);
BLIT_P(G1,0,0,320,240,G0,0,0,320,240);
BLIT_P(G2,0,0,320,240,G0,0,0,320,240);
BLIT_P(G3,0,0,320,240,G0,0,0,320,240);
BLIT_P(G4,0,0,320,240,G0,0,0,320,240);
DIMGROB_P(G1,320,240);
DIMGROB_P(G2,440,25,RGB(255,255,255,255));
FOR T FROM 0 TO 10000 STEP 2 DO
BLIT_P(G1,0,0,320,240,G4,0,0,320,240);
FOR B FROM 1 TO 19 DO
C:=RGB(255-B*12,64,B*12,64);
ARC_P(G1,160+150*SIN(T*(1-B/80)),12+B*22,10,{#0,C});
END;
BLIT(G1);
END;
WAIT()
END;