In The Century of Space Science, edited by J.A. Bleeker, Johannes Geiss, M. Huber, viewed in Google books I ran across the following text and images.
Both satellites are quite stylish looking and have very pronounced alternating white and black stripes.
Presumably the satellites would not be exposed until they are in space when the fairing or nose cone can open, so they would be too far away to see clearly in a telescope so that rotation or tumbling would be visible.
Question: Why were Europe's first few satellites so stylish? Why did they have very pronounced alternating white and black stripes, and had Vanguard-like antennas, but not its shiny reflective metallic finish1,2.
From pages 52 and 53:
The fruits of these investments were soon to be seen. On 26 November 1965, a Diamant rocket rose from the Hammaguir launch pad and placed into orbit the first French satellite, significantly called Astérix. France thus became the third space power and confirmed its claim for an independent role in this important strategic field.
Astérix was a 42 kg test satellite whose role was to confirm the rocket’s ability to place it into orbit. Ten days later, on 6 December 1965, an American Scout rocket launched France’s first scientific satellite, FR-1. This satellite, weighing 60 kg, had been developed by CNES and carried instruments for studying ionization irregularities in the ionosphere and the magnetosphere. It was launched from Vandenberg and placed into a near-circular orbit.
Broglio was quick to react to NASA’s offer of collaboration in space research. In 1962, Italy and the USA signed an agreement for the so-called ‘San Marco’ project, and two eyars later, on 15 December 1964, the first Italian satellite, San Marco-1, was launched by a Scout rocket from Wallops Island. It was a sphere with a diameter of 66 cm and weighed no less than 115 kg. Built by the University of Rome’s Centro di Ricerche Aerospaziali under the direction of Broglio, this was the first all-European satellite to circle the Earth. A second San Marco satellite was launched by Broglio’s group in 1967 from a platform anchored in the Indian Ocean off the coast of Kenya, and the programme continued in the following decade.