If I understand your question correctly, it depends on the gender of the following noun:
bel dom "white house" (masculine)
bela miza "white table" (feminine)
belo pero "white feather/pen" (neuter)
The same is true for all the other color adjectives, except the neuter ending is -e when the stem ends in č, š, ž, c or j: for example, rdeč "red", rdeče pero "red pen/feather".
bel dom "white house" (masculine)
bela miza "white table" (feminine)
belo pero "white feather/pen" (neuter)
The same is true for all the other color adjectives, except the neuter ending is -e when the stem ends in č, š, ž, c or j: for example, rdeč "red", rdeče pero "red pen/feather".
Gavril described the endings for the changeable color words: rdeč, moder, rumen, zelen, vijoličen/vijoličast, oranžen, bel, črn, siv, rjav, zlat, srebrn, bronast, škrlaten, turkizen. These change as most of the other adjectives. Note that sometimes the last vowel is removed when adding a suffix: moder/modra, vijoličen/vijolična, oranžen/oranžna, škrlaten/škrlatna, use dictionary to check for other colours.
The pronunciation of "srebrn" is the same as if it would be spelled "sreberen", but the Slovenian has selected the former spelling. I would usually pronounce it as sre-bə́-rən.
There are also color words that don't change: bež, roza. So the example becomes: roza dom, roza miza, roza pero.