In Exodus (e.g.: 26:14), we learn one of the coverings for the tabernacle is to be made of "תחש" (tachash) skins. The translation of this term appears to be especially difficult or contentious as ...
I see a lot of blue in the tabernacle, and when moving it. For example: Then they are to cover the curtain with a durable leather, spread a cloth of solid blue over that and put the poles in place....