I'm a newbie. I've just about got the basics down for crochet. Squares and circles are pretty good. I'd like to try a square that is 4 triangles, 2 colors. Do I end each color when I add the next? Ex: sc 19 with B completing last st. B ch 1 turn, sc first st then A sc to last st change to B. Pattern shows increasing B one at each end to a point in the middle of the square. I know how to leave a 'tail' and pick it up next row, but I need a tail at each end. Hmmmmm Thanks