The water state of a soil is a fundamental part of the soil color descriptions. Soil color changes if the air contained in the pore space is replaced by water. When this happens, the refractive index of soil particles is more similar to that of the surrounding medium, leading to a decrease in light scattering. Since the color of a soil is dependent upon the distribution of water into the different pores, the water retention function could be monitored by color measurements. Previous studies have investigated the relation between the soil water suction and color using fine earth samples (< 2mm). These repacked samples, however, have lost the natural structure. Our goal was to study the relationships between water retention and color in fine earth and core samples from semiarid soils. Three replicate fine earth (< 2mm) and core (7 cm diameter, 3 cm high) samples from surface soil horizons of two Aridisols (yellow and grey color) and two Entisols (red and black color) were collected in the Desierto de Tabernas (southeastern Spain). The water retention function was determined with a pressure cell apparatus regulated to several pressures: 10, 33, 100, 400, 700, 1000 and 1500 kPa. The moisture levels of saturation, air-dry, and oven-dry at 105ºC for 24 hours were also considered, which represent water retention tensions at -0.1, -10⁵, and -10⁶ kPa, respectively. Soil colors were measured after each equilibrium moisture tension, using a Minolta CM-2600d spectrophotometer. Color of core samples was measured directly on their surface. The fine earth samples were placed in circular aluminum containers (15 mm diameter, 4 mm high) leveling the surface before spectrophotometric readings. For color measurements, we selected the specular component excluded, D65 standard illuminant, CIE 1964 Standard Observer, and cylindrical CIELAB coordinates h_ab, L*, C*_ab, which are similar to Munsell notation but with a wider scale. Soil moisture and color were different in disturbed and undisturbed samples. Moisture content (W) in soil cores was less than in fine earth (mean DW= 3.4), especially in the low pressure range and when the soil has a coarser texture. The color of fine earth was lighter (DL* = 8.8) and more yellow (Dh_ab= 2.3) and chromatic (DC*_ab= 2.7) than core samples. Replication of moisture and color measurements in different samples from a soil horizon equilibrated to a given matric tension was greater in disturbed (mean SD for L*= 0.5) than in undisturbed (mean SD for L* = 3.9) samples. Light absorption in soil samples increased from dry to wet state, until the field capacity condition at -33 kPa. Although color of core samples did not change much for lower pressures, there was an additional slight absorption at -10 and -0.1 kPa. In contrast, there was a clear increase of lightness in the fine earth samples, probably as a consequence of the adherent and plastic consistence that showed these samples at -10 and -0.1 kPa. By this reason, the correlation between moisture tension (logarithmic scale) and L* was better in core samples (mean r = 0.89***) than fine earth (mean r = 0.83**). The relation water retention and chroma resulted stronger in core samples, while the relation water retention and hue was better in fine earth samples. We conclude that for monitoring the water retention function by color measurements we should have care selecting the soil sample type to calibrate the relationships between color and water retention.