The [ALLOW_TEXT_BLEED] token is used to specify that the current textbox will be replaced by an image, using any one of the image tokens, and therefore that the scanning warning 179745 should be suppressed.
Always make sure that the [ALLOW_TEXT_BLEED] token is the first token of a textbox.
Note that this token is only meant to be used in cases when the current textbox will be changed to a picture box, as it will not be replaced (ie. the text [ALLOW_TEXT_BLEED] will remain visible, if the textbox remains a textbox at the end of diary generation).
If you need some color to bleed off the page, then you should set the box contents to None, as discussed in solution 1, here.