On Cloudmonster 2 'Undyed Flame' (3ME10121527)

On Cloudmonster 2 'Undyed Flame'

The On Cloudmonster 2 in Undyed Flame is the shoe that resolves a contradiction that most footwear brands would not attempt: the color of fire, achieved without dye. Undyed is not a colorway in the conventional sense — it is a process, or rather the absence of one. The fibers of the upper retain their natural color, the color they were before the industry decided that performance required transformation. Flame is what those natural fibers look like when On selects them for their inherent warmth: the orange-red spectrum that exists in raw materials before they are altered, the color of the thing itself rather than the color applied to it. The result is a shoe that is simultaneously the most honest and the most striking in the Cloudmonster lineup.

Undyed Flame — The Color of the Material Itself

Conventional dyeing is one of the most resource-intensive processes in footwear manufacturing: it requires significant quantities of water, chemical fixatives, and energy, and it produces wastewater that must be treated before it can be safely discharged. Undyed construction eliminates this process entirely. The fibers used in the Cloudmonster 2 Undyed Flame are selected for their natural color — the warm orange-red tones that exist in certain raw materials before any chemical treatment. This is not a compromise or a limitation; it is a design decision that requires more precision in material selection than conventional dyeing, because the color cannot be corrected after the fact. What you see is what the material is. Flame, in this context, is not a color applied to the shoe — it is the color the shoe already was. The Undyed approach also means that each pair carries the natural variation of the source material: no two pairs are identical in the way that dyed shoes are identical, because the natural color of fibers varies in ways that dye does not. This is not inconsistency; it is authenticity.

Cloudmonster 2 — Maximum Cushioning, Second Generation

The Cloudmonster 2 builds on the original Cloudmonster's maximum-cushioning platform with refinements to the CloudTec® pod geometry and the Helion™ superfoam compound. The double-layer CloudTec® configuration — the defining feature of the Cloudmonster line — is retained and refined: the pods are tuned for a more progressive compression response, providing maximum cushioning at initial contact while maintaining the energy return that makes the Cloudmonster a running shoe rather than simply a cushioned platform. The Helion™ superfoam in the second generation is formulated for improved durability at high mileage, addressing the primary feedback from Cloudmonster 1 users who found the foam's performance characteristics changed over extended use. The upper is On's second-generation engineered mesh — lighter and more breathable than the original, with improved structure at the heel and midfoot for a more secure fit during faster efforts.

Key Features

• Undyed Flame Construction — upper fibers retain their natural orange-red color without chemical dyeing; eliminates the water, chemicals, and energy of conventional dye processes while achieving a colorway that dye cannot replicate
• Natural Color Variation — each pair carries the inherent variation of undyed natural fibers; not inconsistency, but authenticity — the color of the material itself
• Double-Layer CloudTec® — Cloudmonster's signature maximum-cushioning pod configuration, second-generation tuned for progressive compression response and improved energy return
• Second-Generation Helion™ Superfoam — improved durability formulation for high-mileage performance; maintains cushioning characteristics over extended use
• Second-Generation Engineered Mesh Upper — lighter and more breathable than Cloudmonster 1; improved heel and midfoot structure for secure fit at all paces
• Speedboard® — On's propulsion plate tuned for the Cloudmonster's maximum-cushioning stack; converts impact energy into forward momentum

Product Details

• Style Code: 3ME10121527
• Colorway: Undyed / Flame
• Brand: On Running
• Generation: Cloudmonster 2
• Category: Running / Maximum Cushioning / Sustainable Construction
• Upper: Undyed engineered mesh (natural fiber color)
• Midsole: Second-generation Helion™ superfoam with double-layer CloudTec® and Speedboard®
• Outsole: Rubber
• Available in US sizes 7–11

Most shoes are the color they were made to be. The Cloudmonster 2 Undyed Flame is the color it already was. There is a difference, and it matters.