Here we proposed a process to minimize the spectral distortion in IKONOS 1m color image. In this method the 1m multispectral (MS) fused image is processed from 4m MS and 1m panchromatic (PAN) image to which the relations of spectral response between PAN and each band of MS image are obtained most. To maintain this relation, four parameters are added with the pixel value of each band of MS image and Steepest Decent method is used to update the pixel value of each band of fused MS image repeatedly until the color distortion becomes minimum with the maintenance of space information in PAN image as much as possible. Comparison among the proposed technique and existing four processes (IHS image fusion, Brovey Transform, Principal Component Analysis) has been done. Our purposed technique has succeeded to generate the 1m fused image where space information on PAN and MS spectrum information were maintained highly and spectral distortion has been reduced significantly compared to these existing methods.