Why watercolour goes muddy (and how to keep it fresh)
- Blog
- June 25, 2026
- 20 mins
You spend ages on the drawing. The lines are good, the perspective holds, and you are pleased with it. Then you start laying in the colour, and within a few minutes it looks flat, heavy and grey. The natural reaction is to blame the paints, and reach for a different blue.
It almost never is the paints.
First, a reassuring word, because two things often get muddled here. Almost every watercolour looks alarming at the colour stage. Sketchers even have a name for it, the ugly phase: that moment you look down, before any pen or tone has gone on, and feel sure you have ruined a lovely sketch.
Margaret, working through our beginners’ course, put it honestly: she gets “scared of the painting process,” she said, and feels “like I ruin it.” Most of the time, though, nothing is wrong. The colour stage simply looks unresolved, and it comes good as soon as the pen, the tone and the hatching arrive. That happens even when the colour has gone perfectly well.
Real muddiness is a different thing. It is not the stage merely looking odd, it is colour that has genuinely gone dull and grey. And it almost always has one cause: going back in to fix things one time too many.
It is the process, not the paints
So what is actually going on? It is rarely the palette. You more than likely own perfectly good paints.
What happens is mechanical. When we keep working a patch while it is still wet, the pigment piles up, the colours blend on the paper past the point of freshness, and the whole thing dulls down. Adding a different blue or a more expensive tube will not fix that. The cure is knowing when to stop, and letting water do more of the work than paint.
It helps to remember what the watercolour is actually for. It is not the finished picture. It is the first, loose layer. As Ian often says while he paints, “you don’t want to over-paint.” He does not keep pushing more and more colour into a sketch, because if he did, “it’s all going to get lost.”
The colour stage is there to set the mood and the light.
Each stage only does its own job
This is the idea that changes how people paint. In Ian’s way of working, a sketch is built in stages, and each stage only solves so much. The drawing does the drawing. The colour does the colour. The pen, the brush pen and the hatching, which come later, carry the darks, the detail and the snap.
The trouble starts when we try to make one stage do everything. As Ian puts it, a lot of sketchers “try and do too much in each stage.” They overwork the drawing, then pile on too much colour, then too much tone, and by the time they reach the detail stage there is nothing left to do, and no freshness left to enjoy.
The fix is almost relaxing once you trust it. As Ian tells his students, you do not have to win the whole picture with the paint.
"Do a lot less than what you think you need to do in all of those stages," because "the detail stage can fix everything."
How To Keep Your Colour Fresh
The goal, in Ian’s words about one sketch he admired, is “a real nice sketchy, natural quality”: fresh, not laboured. Here are a few habits get you there.
Stop sooner than feels finished. Lay your wash and leave it. If a corner looks a little bare, that is usually fine. You can always add later with far more control than you can take away now.
Reach for water before more paint. If a wash dries too dark, do not fight it with another layer. Lift it gently with a clean, damp brush, or, as we often say, just slap a bit of clean water on it and soften it back. And before you commit to the sketch, it is worth a few practice washes on scrap paper, to get a feel for your pigment-to-water ratio.
Leave some white. Not every shape needs paint. Ian will happily leave a white building as “a big expanse of white,” letting the paper do the work. White space gives a sketch room to breathe.
Let things stay a little ambiguous. You do not have to explain everything. As Ian says, “leave it ambiguous… you let the spectator do the work.” Give them a few telling details and let the rest go. A sketch that tells you less often draws you in more.
Let it dry. So much muddiness comes from going back in too soon. Give a wash a moment to settle before you decide it needs anything else. More often than not, once it has dried, it does not.
The ugly phase is meant to be messy
If there is one thing to take from all of this, it is that the messy, slightly alarming middle is a normal part of the process, not a sign you have failed.
It is one of the most common things we see. A sketcher lays the colour down, starts to panic, and feels certain they have ruined a lovely sketch. Then the line work and the Tombows go on, and the relief is almost universal: it settles, it balances back out, and suddenly it is fine.
The colour stage is supposed to look unfinished. It comes good the moment the pen and the hatching arrive.
And if a sketch still does not come out the way you hoped, that is alright too. The loose, slightly imperfect ones often have the most life in them. On our recent Bath retreat, Karyn dropped a loaded brush of red paint across a sketch, tried to soak it off, could not, and decided she rather liked it anyway.
Final thoughts
World Watercolour Month begins on 1 July, which makes this a lovely time to dust off the paints and put all of this into practice. Keep it light, let the water do the work, and stop a little earlier than feels comfortable. The freshest sketches are nearly always the ones where the brush came off the paper a moment before we thought it should.
Happy sketching.
Ready to learn more?
If colour and watercolour are the parts you would most like to feel surer about, that is exactly what Urban Sketch PLUS is for. Inside you will find dedicated colour and watercolour training, alongside a friendly community working at it together, month after month.
Why watercolour goes muddy (and how to keep it fresh)
About the Artist
Ian Fennelly focuses on capturing urban spaces and environments by drawing the places where people have been without actually including them.
His process involves layering watercolors, brush pens, and liners to build depth, texture, and detail, allowing them to fully immerse in the scene while adapting to changes in their surroundings.
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