The Curious Case of the Changing Label...
From 2013 she was investigated and later tried for fraud and acquitted of corruption involving a company she and her former husband owned. Despite the acquittal, she was stripped of her title of Duchess of Palma de Mallorca by her brother. Also, her Label (the mark of difference on her Coat of Arms) was changed, which is rather unusual.
Some Coats of Arms develop (with inheritances and marriage) and some Royal Labels develop too. In the UK, if a Prince or Princess is the grandchild of a sovereign, they will be assigned a Label with five Points. If the Royal parent then becomes the sovereign that grandchild then moves up a generation and becomes the child of a sovereign and the five-pointed Label will change to a three-pointed one.
This happened with King George V. Although there is no apparent proof that he was assigned a five-pointed Label as the grandchild of Queen Victoria (though not at that stage the eldest son of the prince of Wales) one is shown in a stained glass window in St George's Chapel, Windsor. Not surprisingly, it has a single blue Anchor. When his elder brother the Duke of Clarence and Avondale died he became the eldest son of the Prince of Wales and therefore his Label was changed to three Points. However, when Queen Victoria died and his sisters became the children of a sovereign, namely HM King Edward VII, their Labels remained five-pointed, presumably because there was little point in changing them, plus the fact that two of the three sisters had already married. Maybe it was cheaper not to have to change the letterheads.
However, after Cristina was involved in the court case and when she was stripped of her title, two things happened, more or less at the same time. Firstly, her Label became irrelevant and was changed to a blue Label with a single white Cross to reflect her mother, Queen Sophia's Greek heritage and Arms. This corresponded then at a time when all the Spanish Royal Family's Labels being changed to blue - Cristina's having been blue with the Palm Tree for a short time. The Label of the Heir to Spanish Throne had always been blue and, even though this has resulted in a number of clashes - Cristina's Palm Tree and Infanta Sophia's Roses to name just two - this overall move must have been felt necessary to make Spanish Royal Heraldry more distinctive and consistent.
Cristina's new Label may also be a measure to distance her from her father who abdicated and who has himself caused some controversy.