In the second question of the writing exercise Red Poppies (B2) the way that the preposition "de" changes the meaning of the phrase is not the way I understood that it should be used with colour.
In the exercise we are asked to translate: "red poppies will cover (the Spanish fields)" and the hint goes on to suggest we use: Lit: "the poppies will cover of red", to cover = cubrir. From this hint I was able to assume the required answer should be: "las amapolas cubrirán de rojo los campos españoles"
However, this phrase does not seem to translate well to "red poppies will cover" (that would be "las amapolas rojas cubrirán...) rather it translates more closely to "the poppies will cover the Spanish fields (with) red".
I believe there is a small, but important, difference between these two: one describes the quality (red) that a thing possesses; the other describes an action performed by a thing on another thing (the poppies on the field). Grammatically speaking, in the latter, we could say that the two things in the phrase have a subject/object relationship (in a similar way to how the giver/receiver relationship works in grammar: "Ellas los cubrirán de rojo").
Some examples:
El cielo es azul.
El sol pintó el cielo de naranja.
Llevaba un vestido blanco.
Ella estaba vestida de blanco.
Era una puerta verde, pero la luz del amanecer la había coloreado de rojo.
I appreciate any feedback