Covers 1-3 provided by Russell Whitesell, 4 & 5 provided by sidemachine, 6 provided by Wayne Vincent - I shrunk them to less than 1/3 orignal size
In human forms the three Kikaidas were Jiro (second son), Ichiro (first son) and Rei (zero). I don't know why there was never a Kikaida-00 series.
Bijinda (Kikaida 01 series) was in the comics too.
In the comics Rieko (Kikaida 01 series) transformed as well.
Blue is symbolic of good in Japan, red evil, so with his complete conscious circuit Kikaida would in theory be incapable of doing evil, so no red. And he would be morally perfect so no uneven head or circuits showing. The problem with all this is Kikaida 01 had a complete conscious circuit and was still half red and had electric parts showing.
All black and white pictures and the complete concscious circuit Kikaida picture provided by Wayne Vincent. These pictures are provided to give American (and other) fans who have never seen the comics an idea what they were like.
Kikaida Kikaida 01