The crystallization process in an electrostatically stabilized dilute silica colloid dispersion was studied in an order-disorder coexistence regime by confocal laser scanning microscopy and ultra-small-angle X-ray scattering. In shear-melted homogeneous disordered dispersions, space-filling grains of body-centered cubic lattice were first formed by a conventional nucleation and growth process, which was followed by a lattice contraction resulting in a "cheese-with-holes-like" structure of coexisting ordered and disordered regions. A tentative interpretation was proposed in terms of the long-range interparticle attraction.