Dioxazine Violet (this pigment can be a deeper violet or a redder violet shade)
In 2023, Golden published a vital series of tests on their colors and how they performed in mixes with various white paints. In diluted tints this pigment performed extremely well in both lead and titanium white. More information can be found at https://justpaint.org/astm-lightfastness-testing-for-oil-paints/.