Annem gelinliği sade bulduğu için bukete biraz renk katmak istedi.

In Turkish, family words are often used with possessive endings.

• anne = mother
• annem = my mother

The -m ending means my. So Annem is literally my mother, and here it is also the subject of the sentence.

Here gelinliği is the definite direct object of bulmak.

• gelinlik = wedding dress
• gelinliği = the wedding dress

The ending is the accusative marker, used for a specific object. Also, the final k softens to ğ before a vowel:

• gelinlik
  • -i → gelinliği

So this means the wedding dress, not just a wedding dress.

Bulmak usually means to find, but it can also mean to consider / to think something is.

So:

• gelinliği sade bulmak = to find the wedding dress plain/simple

Here sade is describing how the mother judged the dress. It works a lot like English find something + adjective:

• I found it interesting
• Annem gelinliği sade buldu = My mother found the wedding dress plain

In this sentence, sade means something like:

• plain
• simple
• not very decorative

With clothing or design, it usually suggests a clean, minimal, not flashy look. It does not necessarily mean bad; the sentence just tells us that the mother thought it needed more color.

This is a very common Turkish structure.

• bulduğu comes from bulmak
• için means for / because of

Together, bulduğu için means because she found.

More literally, this is built from a nominalized form of the verb:

• bul-duğ-u
  • bul- = find
  • -duğ- = a subordinating/nominalizing form
  • -u = 3rd person possessive marker

So bulduğu için is literally something like because of her finding or because she found.

In natural English, we just translate it as because she found.

Because Turkish often leaves out subjects when they are clear from context.

The main subject is Annem, and that same person is understood in the reason clause:

• Annem ... bulduğu için ... istedi
• My mother ... because she found ... wanted ...

So Turkish does not need to repeat o (she). The sentence naturally implies that my mother is the one who found the dress plain.

Because için normally cannot attach directly to a simple finite past verb the way English uses because with a clause.

Turkish usually turns the verb into a subordinate/nominalized form first:

• bulduğu için = because she found
• geldiği için = because he/she came
• sevdiğim için = because I like / because I liked

So buldu için would not be the normal structure here.

Bukete is the dative form of buket:

• buket = bouquet
• bukete = to the bouquet

The verb phrase renk katmak uses the thing receiving the addition in the dative case:

• çorbaya tuz katmak = to add salt to the soup
• bukete renk katmak = to add color to the bouquet

So the -e ending is there because the bouquet is the thing being added to.

Literally, it means to add a little color.

• biraz = a little, some
• renk = color
• katmak = to add, to mix in

In context, it can also sound slightly idiomatic: to make something more lively or visually interesting.

So here the mother wanted to make the bouquet look less plain and more colorful.

Because biraz renk is indefinite here.

Compare:

• renk katmak = to add color
• biraz renk katmak = to add some color

This is not referring to one specific, known color as a definite object, so Turkish does not use the accusative.

If the object were specific and definite, accusative marking would be more likely.

İstedi means wanted.

It comes from:

• istemek = to want
• istedi = he/she wanted

It is at the end because Turkish word order is often verb-final, especially in neutral sentences.

So the structure is roughly:

• Annem = my mother
• gelinliği sade bulduğu için = because she found the wedding dress plain
• bukete biraz renk katmak = to add some color to the bouquet
• istedi = wanted

That final placement of the main verb is very normal in Turkish.

Yes. This is a common Turkish pattern:

• verb stem / infinitive + istemek = to want to do something

Here:

• renk katmak = to add color
• renk katmak istedi = wanted to add color

So katmak istedi works just like English wanted to add.

Exactly.

Main action:

• Annem ... istedi = My mother wanted ...

Reason:

• gelinliği sade bulduğu için = because she found the wedding dress plain

What she wanted:

• bukete biraz renk katmak = to add some color to the bouquet

So the sentence is built like this:

[My mother] [because she found the wedding dress plain] [wanted to add some color to the bouquet].