Transforming Spaces: How Joy and Colour Bring Life to Your Home

When interior design meets joy, colour, and personality, something magical happens. A space stops being just “some walls and furniture” and becomes a vivid extension of who we are.

That’s the philosophy behind Rainbow Shaker, the bold, playful interior-design studio founded by Justine Guillermou. Based in East London, Justine brings a unique energy to interiors. She doesn’t just decorate; she transforms. Rainbow Shaker’s aesthetic is all about colour, creativity, and emotion. From the “Colour Your Home Happy™” course to full home renovations bursting with retro palettes and joyful patterns, Justine specializes in turning blank, generic spaces into homes filled with life, memory, and character.

In this conversation, we dig deep into what it really means to design for happiness. We explore how colour, art, memory, and architecture intersect. Even the most reluctant decorator can bring warmth, personality, and soul into their home.

What Does “Bringing Colour and Happiness into a Home” Truly Mean for You?

For me, it’s not about making homes “bright” for the sake of it. It’s about helping people feel seen in their own space. Colour is a language. When used intentionally, it can support your mood, energy, memories, and even your confidence.

Bringing colour and happiness into a home means creating a space that feels alive, comforting, and deeply personal. It’s a place where you exhale when you walk in. Your home should work with you, not against you.

How Does Your Background Influence Your Style and Approach to Interior Design?

All of my experiences shape the way I work. My engineering background provides me with structure, logic, and problem-solving skills. I’m methodical behind the scenes. My French roots bring a sensitivity to colour, art, and emotion (and maybe a bit of a critical mind sometimes 😉). Living in East London keeps me curious, playful, and unafraid of boldness.

My work often sits at the intersection of intuition and structure. I create joyful, expressive spaces that are also deeply functional and thought-through. It’s about colour with intention, not chaos.

How Do You Decide Which Colours, Patterns, or Artistic Elements Best Reflect the Inhabitant’s Identity?

I always start with people, not palettes. I ask questions about their life, memories, and how they want to feel at home. What energizes them? What soothes them? Often, the clues are already there—in their travels, music, clothes, childhood memories, or even the way they describe their “happy place.”

Then, I think about how they live or how they want to live. I mentally put myself in my client’s shoes and retrace their daily routine. I ask questions like: What happens here every day? Where do they slow down? Where do they need energy? This helps me naturally define zones and functions.

From there, colour becomes a tool to translate emotion into space. The goal isn’t to impose my taste but to reveal theirs, sometimes even before they fully realize it themselves.

How Do You View the Role of Art in Interior Design?

Art is always part of the plan 😊. It shouldn’t feel like an afterthought hung on an empty wall. Art can shape the colour palette, the rhythm of a space, and the emotional anchor of a room.

Whether it’s a painting, a sculpture, a handmade object, or something sentimental, art gives a space its soul. I often design around it, not on top of it.

Are There Colours That Universally Bring Joy?

Some colours tend to carry similar emotional weight. Yellows often feel uplifting, blues calming, and greens grounding. But joy is deeply personal. A colour that feels energizing to one person can feel overwhelming to another. Context matters: light, proportions, pairing, and memory.

There are no colours I never use, only colours I use carefully. Even neutrals can feel joyful when done right. It’s never about banning colours; it’s about using them with intention.

The Connection Between Nostalgia, Memory, and Interior Design

Memory is one of the most powerful design tools we have. A colour can instantly transport you to a holiday, a childhood room, or a feeling of safety or freedom (like a Proustian madeleine). When design taps into that, it becomes emotionally grounding.

I often incorporate subtle references: a palette inspired by a beloved place, a material that reminds someone of home, or an object that carries a story. These elements create spaces that feel meaningful, not generic.

Can You Share an Example of a Project Where Joyful Design Transformed the Mood of a Space?

One project that stays with me is a family home that was beautifully maintained but entirely grey. My client described it as “depressing,” especially in winter.

We introduced warm, joyful colours inspired by a family holiday memory, and suddenly the house felt alive. She later told me it had a real impact on her mental health and that she actually looked forward to being at home again. That’s when you realize design isn’t superficial. It can genuinely change how people feel day to day.

How Does Your “Colour Your Home Happy™” Course Help People Express Their Personality?

Most people aren’t “bad at colour”; they’re just scared of getting it wrong. The course removes that fear. It provides a clear, reassuring framework to understand colour emotionally and practically, without jargon or pressure.

I guide participants step by step, helping them trust their instincts. They connect design choices to their own memories and lifestyle, realizing they are creative. They just needed the right language and support.

Does a Home Designed with Colour, Personality, and Art Affect Daily Wellbeing?

Absolutely. Our homes are the backdrop of our lives. When a space supports who you are, it reduces friction, stress, and fatigue. It invites joy, connection, and presence.

Colour and personality make a home feel lived-in, welcoming, and human. When people feel comfortable and grounded in their environment, it naturally impacts mood, energy, and even how we relate to others. Design isn’t just about how a space looks; it’s about how it makes you feel every single day.

Thanks to Justine for taking the time to answer all my questions. It was very insightful.

Talking with Justine reminds me that interior design is so much more than decoration. It’s storytelling, self-expression, and emotional alchemy. Through Rainbow Shaker, she proves that homes don’t have to be a “safe” mould; they can radiate colour, personality, and joy.

Whether you’re renting a small flat, redesigning a whole house, or just curious about turning beige into bold, the path to a happier, more alive home doesn’t start with trend charts or rules. It begins with you: your memories, your emotions, your soul.

So, if you feel drawn to colour, nostalgia, art, or simply something different, trust your instinct. A splash of colour can transform a wall, and thoughtful design can transform a life.

And take a look at her online course, which I have done myself and found extremely useful: Colour your home happy course.

You can also find Justine on Instagram: @rainbow_shaker where she shares her customers' projects and very useful tips, and @thecolourfuldairy her new account where you can follow her journey to completely renovate an old dairy factory into a joyful home in East London.