Looks Central to South African.
Are you sure, Tim?
I can't remember bright pamor-like pattern-welding from that neck of the woods - not my area of expertise though...
Noting that the simple spear head types tend to be very difficult to place positively, I'd assume it to hail from maritime SEA. From the simple base and thickness of the tang, I'd guess this never had any methuk; thus, probably not from Jawa tengah.