It should be repairable. From reading your description it is safe to assume the LCD in the touch screen display has been cracked or damaged. The colored lines, color bleeding, black spots of odd sizes and shapes, visible cracks, and simply the image not displaying correctly are common signs of a damaged LCD.
I have not yet found a step-by-step guide that could help you to replace the LCD yourself. I am sure it's possible but I have not repaired this model before so I do not know how difficult the repair may be. Also some tablets have the digitizer and glass fused to the LCD, while some do not. If the displays parts(LCD/digitizer/glass) are fused together than its easier to replace the whole display rather then trying to separate the LCD from the digitizer and glass. If the whole display is not fused/adhered together than replacing just the LCD is not to challenging. So you may be able to attempt the repair yourself if you feel comfortable doing so, or seek a professional to do the repair.