I have a all in one color LC61 printer, do all colors have to be filled to print blk only?

Greyscale is color not black only.
You can print in black and it will look grayscale only darker, printers are a pain to work with after a year has gone by, I can expect almost a half hour to print something with my $400 epson because one of the colors is out even though I never printed in the last year a colored page. I take the color cartirges out and they are empty, but I only print a page 2-3 times a year. I use the scanner all the time. Brother and epson have their print heads in the printer not the cartridge so make sure your inks are always have something in it or it will be miricle for the printer to last more than a year. Check colors every other week. One Epson printer only lasted 3 months because I never used it(print head dried up). Never use the set up with tubes running outside printer to small tanks of ink if you only use it occationally.