Soie d'Alger® is organized into Colour ranges based on the HUE (pure colour), this is the range name. This arrangement helps when picking colours for thread painting or blending. For a more accurate colour sample you can purchase the shade card.
From the Website:
Au Ver à Soie Soie d'Alger®, trademark registered by Au Ver à Soie®, is an assembly of 7 strands of moderate brilliance easily separable, made from schappe silk (combed silk). It is perfect for all uses in the field of needlework, available in an inimitable range of more than 620 colors.
The Silk of Algiers® does not come from Algeria. The name "Algiers" is linked to a manufacturing process, developed by Au Ver à Soie® since 1820.