Background is avaliable to set like 'transparent', 'red', '#f0f0f0'. Maybe I'll add the function of setting background image.
Left and right gene colors are used when the genes are different. The left gene use the left color. So do the right gene. If the genes are the same, the basic gene color is used. The line under the gene text show the ratio.
CJK characters are avaliable to input for dragons' name. But please change the name font or they may be ugly.