The number of carbs in gluten-free lemon bars can vary depending on the specific recipe and ingredients used. On average, one gluten-free lemon bar may contain approximately 20 to 25 grams of carbohydrates. This estimation accounts for the gluten-free flour, sugar, and other sweeteners present in the recipe. Keep in mind that the carb content may differ slightly based on any modifications made, such as using different flours or sweeteners. Always refer to the specific recipe or nutrition information to get the most accurate carb count.

There could be several reasons why your lemon bars are not yellow:

1. Lack of Lemon Zest: Lemon zest is responsible for giving lemon bars their vibrant yellow color. If your recipe doesn't call for enough lemon zest or you skipped this step, the bars may appear paler.

2. Type of Lemons: The type of lemons used can impact the color of the bars. Meyer lemons, for example, have a sweeter and less acidic flavour than regular lemons, and their juice may not result in a strong yellow color.

3. Lemon Juice Concentration: If the lemon juice is diluted or not concentrated enough, it may not impart a rich yellow hue to the bars.

4. Flour Used: The type of gluten-free flour you use may affect the final color. Some flours are more white or beige in color, which can result in a less vibrant appearance.

5. Egg Yolk Ratio: Egg yolks are responsible for the yellow color in many baked goods. If the recipe calls for a small number of yolks or if you used egg whites only, the bars may not be as yellow.

6. Baking Time: Overbaking the lemon bars can cause them to darken, losing their yellow hue.

7. Food Coloring: Some recipes add yellow food coloring to enhance the lemon bars' appearance, but this is optional.

To improve the color of your lemon bars, consider increasing the amount of lemon zest and using fresh, concentrated lemon juice. Additionally, ensure you are using enough egg yolks and consider using a different type of gluten-free flour if needed.

If you over bake lemon bars, several undesirable outcomes may occur:

1. Dry and Hard Texture: Over baking can lead to the lemon bars becoming dry and hard. The excessive heat removes too much moisture from the bars, leaving them less tender and pleasant to eat.

2. Loss of Flavor: Over baking can cause the lemon bars to lose their delicate lemon flavor. The prolonged exposure to high heat may result in the evaporation of the lemon's aromatic compounds, diminishing the overall taste.

3. Darkened Appearance: Over baked lemon bars may develop a darker color on the top or edges. The sugars in the recipe can caramelize excessively, resulting in a less appealing appearance.

4. Cracked Surface: Excessive baking may cause the surface of the lemon bars to crack. As the bars dry out, they may contract, leading to unsightly cracks on the top layer.

5. Difficulty in Cutting: Over baked lemon bars can become firm and hard to cut cleanly. You may find it challenging to achieve neat and defined squares, making presentation less appealing.

6. Loss of Moistness: Over baking can cause the lemon bars to lose their moistness, making them less enjoyable to eat. The bars may become crumbly and fall apart easily.

To avoid these issues, always follow the recommended baking time in the recipe and keep a close eye on the bars towards the end of the baking process. The goal is to bake them until they are just set and slightly golden on top, ensuring they retain their softness and delicious lemon flavor.

If your lemon bars taste eggy, there are a few possible reasons for this:

1. Egg Ratio: The recipe you used may have an excessive amount of eggs compared to other ingredients. This can result in an overpowering egg flavour in the lemon bars.

2. Egg Size: Using large eggs instead of the specified size in the recipe can lead to an increase in egg flavour, as larger eggs contain more yolk.

3. Mixing Method: If the eggs were not properly incorporated into the batter, you may experience an eggy taste. Ensure you mix the eggs thoroughly with the other ingredients to achieve a smooth and well-blended batter.

4. Baking Time: Over baking the lemon bars can intensify the egg flavour. It's essential to bake the bars just until they are set and avoid excessive baking.

5. Egg Quality: Using eggs that are past their prime or not fresh can contribute to an undesirable egg taste in the lemon bars.

To reduce the eggy taste in your lemon bars, consider the following tips:

- Use the recommended egg size in the recipe.
- Ensure the eggs are thoroughly mixed with the other ingredients.
- Check the baking time and remove the bars from the oven as soon as they are set.
- Use fresh, high-quality eggs for the best results.
- You can also try adjusting the number of eggs in the recipe if it allows for variations.

By making these adjustments, you should be able to achieve lemon bars with a balanced and delightful lemon flavour without an overwhelming egg taste.