The famous Purūṣa Sukta doesn't mention Varṇa Saṅkara-s. Kṛiṣṇa also didn't talk about Varṇa Saṅkara-s despite of concerned raised by Arjuna,
adharmābhibhavāt kṛiṣhṇa praduṣhyanti kula-striyaḥ
strīṣhu duṣhṭāsu vārṣhṇeya jāyate varṇa-saṅkaraḥ - BG-v1.41
though Kṛiṣṇa went on to mention & talk about four varṇa-s. The literal meaning of Varṇa-Saṅkara is corruption of Varṇa, not loss of Varṇa, as if some amount of sand has been mixed with soil. Moreover, as discussed here, the taints of Varṇa-Saṅkara could wither away from society within 7 generations if successive generations are taken care in particular ways (i.e, the sullied soil due to mixture with sand could also be made unsullied). Therefore, it reduces us with only 4 varṇa-s— either pure or impure ones.
So, I wonder if Varṇa-Saṅkara-s have been mentioned in the Vedas? I'm quite aware of several names of the Varṇa-Saṅkara-s mentioned in Smṛiti-s, Mahābhārata, etc. but I am specifically looking for their mentions in the Vedas.
I mean with Varṇa-Saṅkara-s, here, by progenies out of mixture of castes.