As far as I know those are the 6 colors.
Five of the colors were cataloged in various countries, but I don’t believe Red was ever cataloged. I have l all the colors in 0.5 & 0.7 mm, but I have never found the PG603-B.
And then Brazil had the PG620 series, with 0.3, 0.5 & 0.7 mm in one color each. The main difference is the eraser cap does not have the lead indicator, but a PG520 style cap.
Yes, this one covers all basic needs except a wider range of lead sizes. I liked the design enough to get one a couple years ago, and that satisfied the itch. From an aesthetic standpoint, I think the boring clip is a missed opportunity for a more sophisticated look.