Grout Colours: How to Make or Break a Mosaic’s Look
Grouting is one of the hardest—and most important—parts of mosaicing.
You can spend weeks cutting, shaping, and placing tiles, only to change the entire look of the piece in ten minutes flat just by picking the wrong grout colour.
It’s an ever-evolving skill, and honestly, I’m still learning. But here’s what I know so far from years of trial and error (and a few disasters I learned from).
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Why Grout Colour Matters
Grout isn’t just the stuff that fills the gaps—it becomes part of the artwork.
The wrong grout colour can:
Wash out your tiles completely (if it’s too pale)
Overwhelm the design (if it’s too dark or bold)
Flatten the details (if it blends all the shapes together too much)
Shift the mood of the piece (sometimes in ways you didn’t expect)
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Common Grout Colour Choices (And Their Effects)
Here’s what I’ve learned:
White grout:
Usually not my go-to. It tends to wash out the colours, especially softer or pastel tones. It can also highlight any tiny flaws or chips you didn’t notice before.
Black grout:
Great for making colours pop, but it also has a way of blending the design into one visual mass. Use it carefully if you want to keep clear separations between shapes.
Mid to dark grey grout:
This is the safest option for most designs. It supports the colours without stealing attention. If you’re unsure, grey is usually the answer.
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Playing with Pigments and Custom Colours
Lately, I’ve been experimenting with custom grout colours.
I mix acrylic paint pigments directly into the grout, sometimes with a bit of glitter for extra pizzazz. It’s given me more freedom to match the grout to the mood of the piece.
> Note: Grout will always dry lighter than it looks when wet—so plan for that.
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Choosing the Right Shade
When you pick a grout colour, think about contrast:
Choose something a few shades lighter or darker than your tiles—not the exact same tone.
If you match the grout exactly to your tile colour, you risk the design getting swallowed up.
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How to Test Grout Colours: Make a Tile Selection Board
If you’re not sure which grout to use, here’s a trick I recommend:
1. Lay out all the tile colours you plan to use in little groups.
2. Make as many groups as you have grout colours you want to test.
3. Grout each section in a different colour—then let them dry and compare.
This shows you exactly how the grout will interact with your tiles in real life—not just in your head.
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Final Thoughts: Grout Is Part of the Art
Grout is never just filler—it’s part of the design.
It can make the piece sing or drown it out. The only way to get good at it is to experiment, make mistakes, and keep learning.
That’s where the magic happens.
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