29 July 1985,
The Spanish Constitutional Court ordered the withdrawal of the Navarre shield from the Basque Government. The Government of Navarra complied with the request. In 1936 the shield was approved by the first Basque Government, recovering in 1978. Since this judgment, the coat of arms of Navarre is replaced by a painting of red colours. The red color was referenced to the coat of arms of the house of Albret, the lineage of the last kings of the Kingdom of Navarra.
Source:
Frequently asked questions about Basque symbols (Sabino Arana Foundation).