Then again you don't know if the seed is pure Lachenalia pustulata
pollinated by hand or open pollinated hybrids with Lachenalia splendida.

True. Here are Duncan's descriptions, perhaps she will let us know.

Lachenalia splendida:
A gregarious, often dwarf Lachenalia frequenting sandy flats on the Knersvlakte
mainly in the Vanrhynsdorp and Bitterfontein districts, and northwards to
Garies. It was previously known as L. roodeae.
The bulb produces two unmarked, lanceolate leaves and the peduncle is usually7
slightly swollen just below or at the base of the inflorescence. The sessile
flowers are oblong-campanulate in shape; the outer perianth segments are pale
blue at the base, shading to white or pale lilac, and have greenish-brown
gibbosities, while the protruding inner segments are dark lilac with a purple
central stripe. Height 60-250mm

Lachenalia pustulata:
Often found growing in large colonies, this scented Lachenalia has several
colour forms, and occurs on flats and rocky outcrops in the Saldanha,
Malmesbury,Paarl and Worcester districts, as well as on the Cape Peninsula.
The one or two lanceolate or lorate leaves may or may not be covered with
pustules on the upper surface, depending on locality. The inflorescence
consists of numerous oblong-campanulate flowers; in the typical colour forms,
the outer perianth segments are creah or very pale yellow, and have green
gibbosites, while the colour forms found on the west coast in the
Saldanha-Vredenburg districts occur in various shades of pink or blue and have
brownish-pink gibbosites. The protruding inner segments have a dark pink or
brown, or pale green central marking at the tips. It is closely related to L.
unicolor. Height 150-350mm