Mi bufanda azul claro combina con mi camisa blanca.

In Spanish, adjectives usually come after the noun, especially when they describe basic qualities like color.

So:

• bufanda azul claro = light blue scarf
• camisa blanca = white shirt

This is the normal order in Spanish. English often puts adjectives before the noun, but Spanish usually puts them after.

Because blanca agrees with camisa, and camisa is feminine.

In Spanish, most adjectives change to match the noun in:

• gender: masculine or feminine
• number: singular or plural

So:

• camisa blanca = feminine singular
• camisas blancas = feminine plural
• camino blanco = masculine singular
• caminos blancos = masculine plural

Because azul claro is a compound color expression, and in standard Spanish these expressions are usually treated as invariable.

So you say:

• bufanda azul claro
• camisa azul claro
• bufandas azul claro

The same often happens with other color expressions like:

• verde oscuro
• rojo vino
• gris perla

So even though bufanda is feminine, azul claro stays the same.

Here, claro means light in the sense of color.

So:

• azul claro = light blue
• verde claro = light green
• gris claro = light grey

It does not mean clear here. It is specifically describing the shade of the color.

Combina is the third-person singular present tense of the verb combinar.

The subject is mi bufanda azul claro, which is singular, so the verb is singular too:

• mi bufanda combina = my scarf matches
• mis bufandas combinan = my scarves match

So in this sentence, combina means matches / goes well.

Because combinar con is the normal pattern when you say that one thing matches another.

So:

• combinar con algo = to match something / to go with something

Examples:

• Esta falda combina con la chaqueta.
• Tus zapatos combinan con el vestido.

In your sentence, the scarf matches with the shirt, so Spanish uses con.

Normally, Spanish uses a determiner for each noun, so repeating mi is the natural choice:

• Mi bufanda azul claro combina con mi camisa blanca.

If you remove the second mi, the sentence sounds less complete in this context:

• Mi bufanda azul claro combina con camisa blanca — not natural here

So if you mean my shirt, you should keep mi before camisa.

No—mi does not change for gender in the singular.

So you say:

• mi bufanda
• mi camisa
• mi libro
• mi abrigo

The plural form is mis:

• mis bufandas
• mis camisas
• mis libros

So unlike adjectives such as blanco/blanca, the possessive mi stays the same for masculine and feminine singular nouns.

Yes. Combina con is perfectly correct and natural, but in Spain people also often say:

• pega con = goes with / matches
• queda bien con = looks good with

For example:

• Mi bufanda azul claro pega con mi camisa blanca.
• Mi bufanda azul claro queda bien con mi camisa blanca.

All of these are natural, but combina con is a very standard and useful verb to learn.