Colors are given essentially in the UBV system. They are : . total asymptotic colors ubt for (U-B)T . total asymptotic colors bvt for (B-V)T . effective colors ube for ((U-B)e (colors within the effective aperture in which half the total B-flux is emitted) . effective colors bve for ((B-V)e (same as for ube) Total assymptotic colors bvtc and ubtc are corrected for galactic extinction, inclination and redshift effect (see e.g. btc documentation) . HyperLeda . Questions: prugniel@obs.univ-lyon1.fr