The afterimage is flipped to the right. The background sets the overall tone. The deep blue reminds me of ocean, sky, scattered sunlight, our planet seen from space. Blue energizes from beyond. But all colors are tinged with blue, speaking to your intuition.
Several colors are aqua, the watery aspect of our birth and our dreams.
Here we are guided to see subtle differences. The five blue pentagons are intermediate in value, which increases the perception that the blue ground is deepening. The grey is close in value to the background, but pulses to a different heartbeat than the growing green or rosy red. Grey at first seems lacking and sad or sober. It is either unknown or something to change.