Scroll of Colored Ink

The Scroll of Colored Ink is an old scroll created by Ryū Shimizu to seal Matatabi's chakra within him.

As colored ink for scrolls was rare in Shingakure and still is, he considered the scroll to be special in many regards. To ensure he always had access to the scroll, even if someone were to steal it, he used his blood in place of red ink; he could always summon it back that way.

The scroll's symbol is to trick the average human mind into thinking the sealing process was simple. By adding the three clan symbols, he made it seem as though nearly anyone could perform it, but in reality, it took someone with clean chakra. The three characters on it were also made to trick. There was no indication of needing to slam your hand below it for it to activate, so any who attempted it always did so wrong.

Later, when Shizuko finds the scroll, the infuses her clean chakra with the center yin-yang sign, so Sasuke could use it with ease. He never found out, but managed to dig out his out clean ounce of chakra.

Meanings

 * The red symbol is not just to summon the scroll back. It marks the Tailed Beasts who could use fire. It keeps the fire under control for a short while as the jinchūriki comes to terms on how to control the beast.
 * The brown is for Tailed Beasts who uses either earth or wood release. It also proves helpful when removing chakra from the Ten-Tails.
 * The blue is for those with water release. Much like the first two, this helps keep any water attacks under control. When Ryū used the scroll, it also aided him with controlling Matatabi's blue flames.
 * Green remains unknown for the time being.
 * All black and white ink represent the yin and yang, a clear pointer to the need for both nature transformations.