Ive often combined taste and smell i my dreams, especially in the Fall wqhen theres a particular acrid fallen leaf smell that brings on further memories.
Set, its not the color that bothered me but the weird combinations of complementary colors that I find diagreeable when its too jumbled. Ill bet your "watercolor" dreams were associated with a beverage of choice. I recall having dreams following heavy drinking and pizza (espewcially) where there would be copious amounts of blood in all its forms of oxidation (from vermillion arterial blood to deep cordovan dried blood),
Ive never had a watercolor "wash" dream because I was always busy doing watercolors and was in fairly good control of the medium.
In a dream, I could intrvene with some frisket or washout medium and return the highlights to a brilliant white. Ive often had dreams where I was actually painting a watercolor , but this dream was the weird combinations of dumb colors , like the Mardi Gras dcolors and juxtraposed with the Irish Flag.
Holy ****!! I just recalled that yesterday afternoon IO was looking and finding wooden boat kits and several were from the Louisiana CEltic SOciety (Mardis Gras and Ireland) . Wonder if dreams can take off from loose associations like that?