shown like 16bit color image

hi

I just drew some images and import to unity but had some trouble with that color.

[16206-2013-10-06+22;37;58.png|16206]

Adding light effects and alpha images over imported image, it shows me that color bound(?)

some like… 16 bit old image?

How am I supposed to do ?

This effect is known as “banding”. It is, as you correctly said, the result of only allowing a limited number of colours to produce a smooth gradient. This occurs in Unity, usually, because the texture is compressed when it is imported. If you want to get rid of this, then go to the texture import settings in the inspector, and select “Truecolor” in place of “Compressed”. Keep in mind that this does increase the memory usage of the texture.