Custom Colours and Split Finishes for Fiberglass Windows

This guide explains how custom colours and split finishes can be used, what design decisions to consider, and what to confirm before finalizing your Inline Fiberglass window selection.

Windows play a major role in how a home or building looks from both the outside and the inside. Frame colour can help windows blend into an exterior façade, create contrast against cladding, complement architectural details, or become a design feature in their own right.

For projects where standard finishes do not provide the right look, custom window colours and split-finish configurations can provide another level of design flexibility. The key is to choose the finish as part of the overall window specification—not as an afterthought.

This guide explains how custom colours and split finishes can be used, what design decisions to consider, and what to confirm before finalizing your Inline Fiberglass window selection.

What Are Custom Window Colours?

A custom window colour is a finish selected to meet a particular architectural or interior design direction rather than simply accepting a default frame colour.

Custom exterior window colours can be useful when a project calls for coordination with elements such as:

The objective does not always have to be a perfect colour match. In many projects, a complementary or intentionally contrasting colour creates a stronger result.

If colour is an important part of the project, discuss it early in the selection process. Availability can depend on the product and project requirements, so the appropriate finish should be confirmed before specifications and other design decisions are finalized.

Explore Inline’s broader Glass, Colours, Grilles & Hardware Options when planning the complete window appearance.

Infographic outlining custom colour options and split finishes for fiberglass windows, with sections on design, finishes, and planning.
Infographic about custom colors and split finishes for fiberglass windows, outlining design options, finishes, and planning steps for exteriors and interiors.

What Is a Split Finish Window?

A split finish generally refers to a window designed with one colour or finish on the exterior and another on the interior.

For example, a project might call for a dark exterior window frame to complement contemporary cladding while using a lighter, more neutral appearance inside.

This approach allows the same window to respond to two different design environments.

Exterior Design

The exterior colour needs to work with the architecture of the building as a whole. Depending on the design, the goal may be to:

Interior Design

Inside the building, priorities may be very different. The frame may need to coordinate with:

A split finish allows these two sides of the design to be considered independently when the selected product configuration supports it.

When Does a Split Finish Make Sense?

Split finishes are worth considering when the colour that works best outside would not be the preferred choice inside.

A few common design situations illustrate the advantage.

Dark exterior, light interior

Dark exterior window frames are often used to add definition to a façade. That same dark finish may feel too dominant in an interior designed around light walls and trim.

A split finish can preserve the exterior effect while giving the room a different visual character.

Traditional exterior, contemporary interior

Renovations sometimes need to respect an established exterior design while the interior is being modernized.

Treating the inside and outside separately can help bridge those two design directions.

Multiple interior palettes

A larger home or commercial project may use different materials and colours throughout the interior. In these situations, the exterior may need to remain consistent across the building while interior window details are evaluated against the spaces they occupy.

Coordinating windows and doors

Window colour should also be considered alongside entrance doors and other major openings. If the project uses both windows and a prominent front entrance, viewing the products as one exterior design system can create a more intentional result.

Explore the 4500 Series Fiberglass Entrance Doors when coordinating window and entrance-door design.

Choosing the Right Exterior Window Colour

Exterior window colours tend to have a larger visual impact than they appear to on a small swatch.

Before selecting a colour, consider the entire elevation.

1. Decide whether the windows should blend or contrast

A window frame that closely relates to the surrounding material can create a quieter appearance.

A contrasting frame does the opposite. It emphasizes the geometry of each opening and can make windows an important architectural feature.

Neither approach is inherently better. The right decision depends on what the windows are supposed to contribute to the design.

2. Look beyond the siding colour

Windows interact with several materials at once.

Evaluate the proposed finish against: Brick or stone, Exterior trim, Roofing, Metal flashing, Railings, Doors, Garage doors, Soffits and fascia.

A colour that works beside one material may read differently when the entire façade is considered.

3. Consider the architectural style

A contemporary building may use strong contrast and dark frame colours to emphasize clean openings and simple geometry.

A traditional design may use a different approach, such as integrating the windows more closely with trim, masonry or other established details.

The window colour should reinforce the architecture rather than follow a trend independently of it.

Choosing the Right Interior Finish

The inside of the window becomes part of the room.

Before carrying an exterior colour through to the interior, consider how it will interact with the space over the long term.

Think about permanent finishes first

Paint colours are relatively easy to change. Flooring, cabinetry, built-ins and major millwork are not.

When choosing an interior window finish, give greater weight to the permanent elements of the room.

Consider how much visual emphasis you want

A contrasting frame draws attention to the window opening and the view beyond it.

A quieter finish can allow furnishings, architectural details or the outdoor view to carry more of the visual weight.

Look at more than one room

For projects using a consistent window system throughout the building, consider whether the selected interior finish works across bedrooms, kitchens, living spaces and other areas—not just in the room used for initial design decisions.

Custom Colour or Standard Colour?

A custom colour can be valuable when the window needs to satisfy a precise design requirement, but that does not mean every project needs one.

A standard finish may be the stronger choice when it already coordinates successfully with the rest of the project.

Consider moving to a custom colour when:

The decision should be driven by the architecture rather than customization for its own sake.

For projects that involve broader changes to size, configuration, glazing or finishes, review Inline’s Custom Fiberglass Windows options as part of the planning process.

Plan Window Colour Early in the Project

Colour decisions can affect more than the appearance of an individual window.

Architects, designers and homeowners may need to coordinate the final window selection with drawings, exterior materials, trim details and door selections.

Making the colour decision early gives the project team more opportunity to evaluate everything together.

Before finalizing a custom colour or split finish, confirm:

These details should be confirmed for the specific product and project rather than assumed from another window or door configuration.

Use Samples and Real Materials Whenever Possible

Colours viewed on a computer monitor are not always reliable representations of a finished product.

If finish samples are available for the product being considered, compare them with the actual project materials whenever possible.

Review the colour beside: Brick or masonry samples, Siding, Roofing, Exterior metal, Interior paint, Cabinetry, Flooring
Door finishes.

It is also useful to view the materials under different lighting conditions. A finish can look different outdoors, indoors, in direct sun and in shade.

For design-driven projects, a showroom visit can make these decisions easier by allowing several window and door details to be considered together.

Custom Colour Is Only One Part of the Window Design

Colour is important, but it should be selected as part of the full window package.

Depending on the project, the overall appearance may also be influenced by: Window style and operating type, Glass selection, Grilles or SDL details, Hardware, Exterior trim, Interior casing, Window proportions, Adjacent entrance doors.

Reviewing these elements together helps prevent individual selections from competing with one another.

The Glass, Colours, Grilles & Hardware Options page is the best starting point for exploring how these design choices work together.

Common Questions About Custom Window Colours

Find clear answers to common questions about Inline fiberglass windows custom window colours, and how to choose the right solution for your project.

Colour availability should be confirmed for the specific Inline product and project. If you have a particular colour in mind, provide the reference during the design or quoting process so the team can advise on available options.

That type of configuration is generally known as a split finish. Availability should be confirmed for the selected Inline window system before the design is finalized.

Colour matching refers to selecting or developing a window finish intended to coordinate with another project colour or material. The exact colour-matching options and process should be reviewed with Inline for the specific project.

Custom finishes can involve additional project requirements. Confirm any scheduling implications during the quoting process rather than assuming the timing will be the same as another finish.

Warranty treatment should be confirmed for the specific finish and product before ordering. Review current warranty information and ask the Inline team about any finish-specific conditions that apply.

Ideally, these decisions should be made together. Windows, doors, cladding, masonry, roofing and trim all contribute to the finished elevation.

Windows and doors can be planned as part of the same exterior colour strategy. Exact finish availability and coordination should be confirmed for the specific window and door products selected.

Plan Your Window Finish With the Full Project in Mind

Have a colour direction or split-finish concept in mind? Request a Design Consultation to review your project, explore the appropriate Inline Fiberglass options and confirm the finishes available for your selected products.