The cloth of blue
does not have the same hue or intensity of colour as the cloth that envelops the ark of the covenant, which is to be a cloth all of blue
(ESV) or pure blue.
It is in cloths of blue
that the table, together with the other items of the Holy Place, will be enveloped. This colour thus shows that they belong to the Holy Place and take a second rank after the ark of the covenant.
7 And over the table of the bread of the Presence they shall spread a cloth of blue and put on it the plates, the dishes for incense, the bowls, and the flagons for the drink offering; the regular showbread also shall be on it.