[Q] Why the display of custom roms are not bright and colourful? topic

When i flash a ported rom on my Xperia s lt26i then the display quality while watching videos is good,that means its as like my stock official rom(Brighter and colorful) but in other custom roms its not brighter and the screen display is like some ordinary phones feels this is not a sony phone.is there any solution to this or its usual?If any of my friend agree with me then share this to reach any developers to answer this....