Android does come with 2 default color scheme : Holo light and Holo dark.
I was wondering, is it advisable to use own color scheme in Android app? What kind of consideration we should taken in, when designing our own color scheme?
It depends on your circumstances really. However, the main point of "custom" color schemes is to make your app stand out, but that is really a design choice. From a UX view, Kayo is right. If the app is so customized that it becomes hard to use/unfamiliar to the user, then that is a problem.
Custom colors/textures could be useful, as if you had a completely white app design the User would quickly become annoyed at the design, and perhaps ditch it quickly. Other color schemes cause things to be hard to find, not enough contrast, etc.
However, you really need to do three things here.
Leave it pretty much up to your designer to choose the colors/textures, and what not. They know best.
Your job is to position and alter the ui elements, not what they look like. Make sure you don't become absorbed into colors, when you should be positioning things to look normal.
If you don't have a designer, then you will need to worry about colors, but just think logically. Usually the standard colors are more familiar to the user, and make more sense. However, you can put colors to good use, like highlighting the "delete" button red, which almost puts a sense of danger into the user's mind.
As an example of poor UX-color design, take a look a one of my greatest annoyances at Apple.
See how the "History button is colored darker than Top Sites, even though we are on Top Sites. This is a terrible idea. Darker shades are universally known as being the selected item, so doing it this way is confusing and counter-productive. If MOST apps did this, then fine, but they don't. Follow the standard.
Second, examine another design element (by Apple), that as a UX person, you should fight against.
That button, is actually two buttons. You have an eject side, and a side that selects your phone. Stupid! Even I could not find a way to sync my iPod because it looked like there was only an eject button.
The point here is, design does affect UX. Usually you don't need to worry about it too much, but there are definitely cases of it becoming annoying, confusing, and counter-intuitive. Colors are like that, do what you please, but don't color the "Cancel button red, and the Delete button gray".
I would of thought that standardising your input boxes, buttons, links, layout and form elements etc would be more important than the colour scheme.
On iOS having a menu swipe in from the left or right has become commonplace for modern apps (see facebook app). This type of functionality consistency is way more important than the colour choice (in my opinion).
The colours used in your app should be used to highlight and raise or lower the importance of individual elements. Regardless of colours chosen as long as that is conveyed I think you're good.