"I have loaded a picture for a new design, but Flood Fill covers the whole picture when I try to fill colored areas of the picture."
Pattern Flood Fill and Cross Flood Fill are not affected by areas of color in a background picture. An empty area of the design can be flood filled until it meets existing crosses and backstitch. A connected area of the same colored crosses can be flood filled until it meets an empty area, backstitch or crosses in a different color. To clearly see the areas that will be flood filled, turn off the background picture.
"Flood Fill does not fill the whole area as expected."
In some cases, Flood Fill and Cross Flood Fill will not go through narrow areas. If the fill could not continuously connect a fill of full crosses through a narrow gap, the gap will act as a barrier to the flood fill.
"I have a pattern that uses freehand backstitch. When I use it to fill an area it does not seem to fill the area completely or some lines of freehand backstitch appear to be missing."
When a pattern is used to fill an area, freehand backstitch in the pattern will only be placed when both end points lie within the fill area. Long sections of freehand backstitch are less likely to have both ends in the fill area and may not give the desired result. If you wish to use freehand backstitch in a pattern, try to use short sections where possible.