Android颜色int和RGB相互转化

将RGB转化为int：

int color=Color.rgb(red, green, blue)

如果需要透明度

int color=Color.argb(a,red, green, blue)

将int 转化为 RGB

int red = (color & 0xff0000) >> 16;

int green = (color & 0x00ff00) >> 8;

int blue = (color & 0x0000ff);

获取图片中的颜色：

ColorDrawable drawable = (ColorDrawable)holder.itemView.getBackground();
            int color = drawable.getColor();
            int alpha = drawable.getAlpha();

            int red = (color & 0xff0000) >> 16;
            int green = (color & 0x00ff00) >> 8;
            int blue = (color & 0x0000ff);