Someone else suggested yellow for light, because Jesus is the light of the world, and when the sun shone it would cast a yellow glow of light around the room.
Someone else suggested blue, because it reminded them of the power of the sea, the sky and the creative power of God.
They each debated the merits of their suggestions, but then the artist turned around and showed them her sketch. The window had clear patches and blue and yellow patches, but where the three colours overlapped there was the most amazing emerald green. The window was duly made, and the three colours used, but the centre of the window was the most beautiful part of all.
We each have of our own vision of God, but when we put them together, when we look at God the Father, God the Son and God the Holy Spirit, then our understanding of God is far more beautiful than we could ever imagine.