Wave motifs

Wave motifs, also known as koros, are graphic elements that are inspired by the City of Helsinki crest. The goal of using a koro shape is to bring visual interest to the identity.

See the Koros component documentation for instructions on using Koros in implementation.

Visual principles

Shapes

Wave motifs are available in six (6) different shapes:

Calm (Tyyni)
Basic (Perus)
Pulse (Pulssi)
Beat (Syke)
Vibration (Värinä)
Wave (Tyrsky)

Size

Wave motifs can be used in any size if at least two wave tips are visible per surface. However, it is recommended to use one of two HDS provided sizes; Default or Dense.

Angle

Wave motifs can be used in any 0, 90, and 45 degree angles.

Koros are allowed to be rotated in 45 degree increments

Colour

Wave motif colour selection follows these guidelines:

Only one color per one wave motif shape (no gradients or multiple colours)
Any of the City of Helsinki Primary colours can be used as well as Black and White
- Grayscale colours are not recommended
  - If you need a gray colour, use the brand colour Hopea (Silver) instead
- Secondary and Accent colours of the palette must not be used

Additionally, a Koro shape can also act as a mask for an image.

Usage

Where to use

Wave motifs are used to visually divide surfaces from each other.

Using Koros to separate sections from each other

However, pay attention to the contrast between section backgrounds. Be cautious when using stark colours that have a large contrast ratio between them.

Pay attention to colour contrasts when using Koros to separate sections

One common use case for Koro shapes is to use them to visually separate elements from each other. For example, to separate a text area from an image.

Koros can be used to visually separate elements from each other, e.g. text areas from images

Koro shapes should not be used as an accent element. They are purely meant for visual purposes.

Koro shapes should not be used to accent elements, e.g. to indicate an active state

Which size and shape to use

Follow these rules when using wave motifs:

At least 2 full-wave motif “tips” visible per surface
It is recommended to use HDS provided sizes (Default and Dense)
- It is recommended to choose one size and use it throughout the whole service
Shape can be freely chosen (from the premade 6 shapes) by the service
- It is recommended to choose one shape and use it throughout the whole service

Dos and Don'ts of Koro shape and alignment

Be cautious when mixing Koro shapes and sizes. It is a good practice using one shape and size across the whole service or page.

HDS components that use Koros

HDS includes a few components that have wave motif support built into them:

Footer

Animation

It is allowed to animate wave motifs. While this is not directly supported in the HDS Koro component, you can find downloadable wave motif animation from the Helsinki Brand website - Downloadable Wave motifs section.