- Hittite midis ~ mi[d/t]as 'red'
- Mycenaean *miltos 'red mineral' (> Gk μίλτος 'red chalk')
- Egyptian mnš.t 'red ochre'
- Latin minium 'red lead'
Now if we accept that there is a Minoan word here, what is its likeliest form? This has got me thinking hard and long because while there appears to be a relationship between the above words, finding a common etymon behind them all is tricky. For me, Hittite, Egyptian and Mycenaean all point to a general structure of *miN(T)- (N = resonant, T = coronal). The Latin word, which we might assume is from Etruscan, strangely doesn't reflect the expected coronal. At this point, it's understandable that one might decide to abandon this idea altogether due to a lack of consistency. However, for the sake of brainstorming, I thought of one elaborate possibility.
Let's suppose that there was an Aegean root *minyu 'red-orange mineral dye'. From this, let's also suppose that Minoan added an optional suffix *-zo (cf. Etruscan diminutive *-za), thus Minoan *mĩyuzo. This can then yield all of the Hittite, Egyptian and Mycenaean reflexes at once. In Etruscan however, inherited *miniu, without suffix, would yield Latin minium 'red lead'. Now we just might be able to explain this whole package of possible substrate. Maybe outlandish but it was worth a shot.