The ambition of the PROPTITEX project is to create fabrics capable of locally and controllably changing color. This ambition is based on the results of the initial project consisting of the integration "into textiles," directly onto the filament/textile fiber/thread of electrochromic (EC) compounds, allowing EC textile threads to change color in a controlled manner. The objectives of the PROPTITEX project are: 1. Design and realization of an EC textile thread using REACH-compatible products; 2. Implementation of a textile structure (knitted, woven, or embroidered) using the EC thread; 3. Design and realization of the EC connection of the EC textile structure based on its architecture (20 x 20 cm2); 4. Evaluation of the performance and durability of EC structures for civilian and military applications; and 5. Life cycle analysis, circular economy, and recycling of EC structures. The PROPTITEX project addresses both military and civilian challenges. In the military sector, as indicated in the initial project conducted by the LPPI laboratory, the development of adaptive optical systems for camouflage and stealth technology in military equipment has become a major issue to protect soldiers and equipment in combat theaters. Among the technologies developed, electrochromic materials are particularly interesting in the visible domain. The security, economic, and societal stakes in the event of conflicts are evident. In the civilian sector, the possibility of developing threads, which are the basic elements of fabrics capable of changing color, could open up a new and very promising field of application for fashion designers involved in the luxury and fashion industry. The potential to partially integrate color-changing design elements in luxury bags or within clothing could increase the value of these products and allow the French fashion and luxury industry to differentiate itself from its global competitors. Moreover, the development of EC threads capable of changing color will rely on materials that comply with the European REACH regulation (Regulation No. 1907/2006), which came into effect in 2007 to secure the manufacture and use of chemical substances in the European industry. Environmental impacts throughout the life cycle of the developed EC materials and components will be addressed through the implementation of the life cycle assessment (LCA) methodology. The LCA study will follow the ISO 14040/14044 and ILCD Handbook guidelines and will include the following stages: definition of objectives and scope, life cycle inventory (LCI) based on data on the inputs and outputs of the system (which will be provided by LPPI), life cycle impact assessment (LCIA), and interpretation. The environmental impact is quantified in impact categories, which are included in several methods (e.g., Eco-Indicator99). Environmental impact categories to be analyzed include climate change, depletion of the ozone layer, ecotoxicity, human toxicity, resource use, and depletion, and cumulative energy demand, among others. The LCA analysis will enable a comparative study of the potential environmental impacts of different EC thread and structure manufacturing solutions (technology, raw materials, process energy consumption).