Using cold water to wash a garment that specifically states "warm wash only" can have several potential consequences beyond just affecting the color:
Cleaning Efficiency: Warm water is generally more effective at removing dirt, oils, and stains compared to cold water. If the garment requires warm water for proper cleaning, using cold water might not effectively clean the item, leaving it less fresh and potentially retaining stains.
Detergent Performance: Some detergents are formulated to work optimally at specific water temperatures. Using cold water when warm water is recommended may result in the detergent not fully dissolving or activating, leading to less effective cleaning.
Residue and Odors: Washing in cold water might not rinse out detergent residues and fabric softeners effectively, leading to buildup over time. This can cause the garment to feel stiff, look dingy, or develop unpleasant odors.
Shrinkage and Damage: Certain fabrics are more prone to shrinking or experiencing damage when washed in cold water. Warm water can help relax fibers and minimize the risk of shrinkage.
Color Bleeding: While you mentioned it, color bleeding is still a relevant concern. Warm water can help set dyes in some fabrics, reducing the risk of colors bleeding or fading during the wash.
Fabric Care: The care instructions provided by the manufacturer are designed to ensure the garment's longevity and performance. Ignoring these instructions, such as using cold water when warm water is advised, might lead to premature wear and tear of the fabric.
It's essential to follow the care instructions on your clothing labels to maintain the garment's quality and appearance. If you don't have access to warm water for washing, you could consider handwashing the item gently in lukewarm water as a compromise. However, using cold water on a garment specified for warm wash only should be done with caution and only if you are willing to accept the potential consequences.