Coloured weed?

What would happen if you only watered your plants with water that has food colouring in it, like blue or red for example?

yes food dye will help change the color but only use small amounts

Would it be a noticeable change?

no it wouldnt change the color at all, food coloring wont be absorbed by the roots, if you want to dye your buds do this, https://www.rollitup.org/general-marijuana-growing/9902-color-my-dreams.html
ps dont listen to ppl who have no posts or rep, they will tell you things that they think are true but they really have no idea