Rebutia (Aylostera) pallida was first described by Walter Rausch in Succulenta 56(10) p. 234, with a colour photograph on p. 233.
Here is the text of the description in Latin as published, with my own English translation below. You should look up the original description for further details included additional notes in Dutch.
Rebutia (Digitorebutia) pallida Rausch species nova
Simplex, brevicylindrica, 30 mm alta et 20 mm diametiens, glauca et violaceo-asperata, radice napiformi magna carnosa; costis 13-14, recte adscendentibus vel paulum tortis, undulate in gibberes 3-4 mm longos et latos divisis; areolis ovalibus, 1 mm longis, fusco-tomentosis; aculeis marginalibus 9, ad 3 mm longis, accumbentibus, setosis, vitreo-albis, basi fuscis; aculeo centrali 0. Floribus lateralibus, 20 mm longis et diametientibus; ovario et receptaculo violaceo-rubro, squamis atro-fuscis et pilis albis tecto; phyllis perigonii exterioribus roseis, medio-fusco-striatis; phyllis perigonii interioribus spathulatis, serratis, roseis, medio-clare aurantiacis; fauce grisea et subconnata, filamentis albis, stylo et stigmatibus (5-6) viridibus.
Patria: Bolivia, Cinti meridionalis , apud La Cueva, 3.500 m alt.
Typus: Rausch 645, depositus in Herbario Collectionis Plantarum SuccuÂlentarum Municipali Turicensi, Helvetia.
English translation
Rebutia (Digitorebutia) pallida Rausch species nova
Single, short-cylindrical, 30mm high and 20mm in diameter, glaucous and suffused with violet, with a very fleshy tap root; 13 – 14 ribs, ascending vertically or slightly spiralling, divided laterally into tubercles 3 – 4mm long; areoles oval, 1mm long, brown-wooled; 9 marginal spines, up to 3mm long, flattened, bristly, glassy white with a darker base; no central spines. Flowers arising from the sides, 20mm long and the same diameter; ovary and receptacle violet-red with dark brown scales and covered in white hairs; outer petals pink with a darker central stripe; inner petals spatulate, serrated, pink, with a pale orange centre; throat grey and fused below, white stamens, green style and stigmas (5 – 6).
Habitat: Bolivia, central Cinti, above La Cueva at 3,500m altitude.
Type: Rausch 645, deposited in the Herbarium of the Municipal Succulent Plant Collection of Zurich, Switzerland.