This question comes up constantly, and honestly, I love getting it — because the answer isn't about which one is "better." It's about what your specific book actually needs to do for its reader.
Full color is the standard for picture books aimed at younger readers, roughly ages 0 to 8. Every single page is its own piece of original art — background, characters, lighting, mood, all of it. That's exactly why it costs more than black-and-white work: you're not paying for "extra ink," you're paying for a fully realized painting on every spread.
If you're writing a picture book meant to be read aloud, pored over, and looked at as much as listened to, full color usually isn't optional. It's part of how the story gets told.
Black-and-white, or line art, shows up most often in coloring books, activity books, and books for slightly older readers. It's a real artistic choice, not a lesser one — clean line work done well is genuinely striking, and it opens the door for interactivity that full color can't: your reader can color it in themselves.
Ask yourself what your book is for. A bedtime picture book meant to be visually immersive? Full color, almost always. An activity book meant to be colored in, or a book for older readers where illustration is a light accent rather than the main event? Black-and-white might be exactly right, and it'll stretch your budget further.
Neither choice signals a "cheaper" or "less serious" book. It signals that you understood your reader and your format before you started spending money — which is exactly the kind of decision that makes a book feel intentional instead of accidental.
