Solution:

Solution:

It is perfectly alright if you were not able to. The thing is that sometimes, our mind conflicts with the abundance of information that is provided to it. In this image, the color does not fits with the description. Our mind now knows and recognize all the colors. This is the reason when you come across a color with a different description that suggests another color, our mind is not able to produce the final result in a flow. This might not happen with all but happen with most of the people.

Solution:

Yes that center dot is no doubt grey. You can check it in any image editing software. You can even check by covering the surrounding dots with your hands. You will realize that it is indeed Grey only. So why does it appear green? It is because of the surrounding colored dots and the background color. Our mind is forced to perceive that it is actually green. Let us give you another shock now. What if tell you that all the other green dots are also grey actually? Surprised? Go check out for yourself.

Solution:

Of course, there is no glow surrounding it. But yes, it is visible and is perceived by our brain. But why? The color of the background has not been interfered with and it is uniformly black. But the one that is into the play is the black lines which have been drafted to shape a heart inside the figure. It is actually changing the contrast of the image on those regions which are responsible for the neon glow surrounding the heart. You can check the image in any editing software and you will not find any difference between the background yellow shades.

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Solution:

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Solution:

Now this effect is commonly used in so many basic illusions as well as complex ones. The logic behind it is that the tinted orange color wave-lines are creating an illusion on the background. The tint effect cannot be seen with the purple colored lines. While purple is promoting the white background, the orange color is creating its own tint in the background.